If you want to know why a converted herring warehouse in Copenhagen could be considered the best restaurant in the world, you could do worse than to lean your bicycle against Noma's weathered brick wall and come in to take a look at its most famous dish, a preparation that would be listed on the menu, if the restaurant bothered to give you a menu, as The Hen and the Egg.

A plate of damp hay appears, smoldering under the empty, superheated pan that rests atop it. A squeeze bottle is produced: You are directed to squirt a few drops of hay-infused oil into the pan, and then crack a speckled wild-duck egg into the oil. A timer is set. The egg white bubbles and spits. When two minutes have elapsed, you are instructed to swirl a knob of goat butter into the pan and briefly sauté a few fragile leaves of spinach and of ramson, a kind of wild garlic that may have been gathered that morning in a nearby city park.

At Alinea in Chicago, chef Grant Achatz conjures up Apple Horseradish Celery Juice and Leaves. Photograph by Lara Kastner

A chef brings over a tiny saucepan of forest-green ramson oil, which he spoons over the cooked white. You scatter herbs and wildflowers, and break off whorls from a potato-chip helix. The fragrance of Nordic spring drifts from the pan: the distant smoke, the dampness of thawed earth, the secret pungency of the forest floor. You have discovered what it might be like to fry an egg in the spring woods if you had perfect ingredients and the resources of one of the world's great kitchens. A hundred tiny things have been orchestrated to ensure that you will be eating the best fried egg of your life.

You glance across the harbor at a ferry coming in from the remote Faroe Islands, and you snuggle into the sheepskin draped over the back of your bentwood chair. You take a sip of wine. The vivid, orange yolk oozes down your throat like congealed sunshine, like jellied time.

Noma—its name is an abstraction of the phrase nordisk mad, Nordic food—was just named World's Best Restaurant on the 2011 San Pellegrino World's 50 Best Restaurants list, as voted by the more than 800 members of The World's 50 Best Restaurants Academy and presented by the British trade journal Restaurant. Noma was also the World's Best Restaurant last year, supplanting the four-year reign of Spain's El Bulli.

Who is in The World's 50 Best Restaurants Academy? Pretty much whom you'd expect to be in a group like that: editors, chefs, consultants and turnip cognoscenti. Have the voters eaten in the restaurants they're judging? They're supposed to have—sworn to have, actually, within the 18 months preceding the voting. Does this mean the lists are susceptible to fads, as novelty-seeking voters flock to Modernist-cuisine restaurants one year and forager-intensive restaurants the next? I'm afraid it does. And an obscurely located chef like Michel Bras, stuck in the knife town of Laguiole, is never going to do as well as, say, Pierre Gagnaire, whose experiments are right there in Paris.

If you're wondering whether an American restaurant has ever made the cut, the answer is yes: The French Laundry, Thomas Keller's Napa Valley shrine to finish-fetish Franco-American gastronomy, won the award in 2003 and 2004, flanked by El Bulli's win in 2002 and four-peat from 2006 to 2009. The restaurants celebrated by the San Pellegrino list tend to be international in character, if not necessarily in ingredients, so you will often, for example, find French restaurants in New York outranking the ones in Paris, and the most ambitious young chefs these days drift from the French Laundry to Noma to Alinea to El Bulli in the way that they used to go from Troisgros to Bocuse to Guérard.

Alinea's chef, Grant Achatz Photograph by Lara Kastner

Still, Noma is in Copenhagen, which is not on the way to anywhere, unless you're planning on taking the bridge to Malmö. And its chef, René Redzepi, a young Dane whose commitment to organic, sustainable local products out-Berkeleys even Alice Waters, has invented a direct, poetic style of cuisine that echoes in Tokyo and Beverly Hills, where a Vietnamese restaurant—a Vietnamese restaurant!—mimics his style down to the pickled rose petals and the dabs of buckthorn jam. Next year may see the ascension of Osteria Francescana or Le Chateaubriand or Alinea, but for now, Noma, home of that fried egg, is plausibly the best restaurant in the world.

When news broke that Noma had won the title again, I got on the next flight to Copenhagen—or rather the first flight on the date a reservation could be booked, which for a 12-table restaurant just reconfirmed as the best in the world, took a couple of weeks.

In the meantime, I managed to snag a table at Alinea, which at No. 6 was merely the Best Restaurant in North America. Alinea too is an impossible table—it's like getting great tickets to a Cubs game, except that there isn't a line of scalpers camped across the street, and you can't get a hot dog. The guidebooks say "reservations strongly suggested," which is like saying it's a good idea for your children to apply to Harvard if they want to go to that school. Suffice it to say that chef Grant Achatz's new Chicago restaurant, Next, sells its seats through its own online system, and adjusts prices according to a demand algorithm similar to the ones used by airlines.

Alinea is marked by a discreet monochrome sign, but you will pass the dimly lighted doorway the first three times you encounter it, and the homeless person on the corner, who knows full well why you are rocking a dark suit in this unglamorous corner of Chicago's Lincoln Park, will point you in the right direction for a fee.

One of the restaurant's 22 courses, sea urchin encased in vanilla gelée Photograph by Christian Seel

You announce yourself, and pass through tall metal doors that whoosh open like the entrance to the lair of a Bond villain. All is luxury, specifically the gray, understated brand of luxury. If you're the kind of person who read the High/Low charticles in the late Metropolitan Home, and knew exactly why one mahogany end table cost $25,000 more than its apparent twin, you will feel right at home.

If you are a little early, you may be invited into the Alinea kitchen, which is an extraordinary place, a big space, practically a ballroom, gleaming-clean as an operating theater, filled with serious men and women bent like jewelers over their work stations. It is quiet in Achatz's kitchen; no yelling, no music, no clatter of plates. There are also no range hoods, no internal dividers, and no visible flame. And you don't smell anything either. The cuisine seems less cooked than willed into existence.

Achatz worked for years as the No. 2 under Thomas Keller at the French Laundry, and had a thunderbolt conversion to Modernism during a short stage at El Bulli. Gourmet magazine famously named Alinea the best restaurant in America in 2006.

Back then the cooking at Alinea brought to mind the earliest days of performance art, when the body (or the food) became essentially an extension of the elaborate hardware built to support it, a sculptural element rather than a thing in itself. Among the 17 to 22 tiny dishes in a typical tasting menu, there is a cube of sugarcane dusted with dried shrimp that evokes precisely the taste of the grilled Vietnamese shrimp cake called chao tom (you spit the fibrous remnants into a napkin), and a leaf whose steely brininess mimicks that of a fresh oyster; the tofu skin called yuba rolled, fried crisp, garlanded with strips of shrimp and jammed like a fountain pen into an inkwell filled with spicy miso; sea urchin encased in vanilla gelée perched over a bowl of hot green garlic soup; and a dish of minuscule cremini and maitake mushrooms whose plate is perched on an inflatable pillow filled with pine smoke.

Chicago's famous skyline Photograph by Lara Kastner

Is it quibbling to suggest that the delicate fragrance of maitake, a mushroom prized for its aroma of pine, was obliterated by the seepage from the pillow, and that nearly every dish was oversalted to the same, undoubtedly intentional degree? Is it merely clever to scent an all-white dish of halibut, parsnip curls and almond with the jet-black aromas of pepper, licorice and coffee? Is trotting out a version of a classic Escoffier dish, in this case slightly overcooked lamb with seared potatoes and a sauce Choron, the equivalent of Picasso executing the occasional formal portrait to prove that he knows that human eyes do not stack like those of a turbot?

The idea of restaurant as theater has become a cliché, and every chef who manages to sous vide an artichoke without electrocuting himself has been declared a genius, but Achatz's handiwork is still better explained in theatrical terms than in culinary ones. As in a melodrama, you know that the flags presented in the first act are going to come into play in the fourth (they turn out to be sheets of fresh pasta, meant to be wrapped around braised shortribs, with dabs of fermented garlic, smoked salt, halved blackberries and tobacco sabayon). A dramatic serving bowl is always going to come apart in sections, so that you experience the combination of rabbit and squash first as a cold mousse, then as room-temperature rillettes with blood sausage, and finally as a cinnamon-scented consommé kept hot with a roasted rock.

You are personally going to pull the pin that drops the hot, truffled potato into the chilled potato soup—you down it like a whiskey shot—and you are going to hunt around for the cube of venison in the bowlful of eucalyptus leaves. You are going to follow the waiter's instructions as you scrape yuzu "snow" out of a metal cone frozen with liquid nitrogen, rescue fruit leather–wrapped dessert bacon from its bondage apparatus, and suck finger-lime Jell-O from a capillary tube plugged with dragonfruit. You will shrink into the banquette as Achatz himself flings blueberries, honey custard and fuming liquid-nitrogen mousse onto a silicone tablecloth that has been laid out for the dessert course, and you will watch in amazement as the globs of chocolate gradually rearrange themselves into squares. Alinea is a house of marvels, the restaurant equivalent of Cirque du Soleil.

The Alinea dining room Photograph by Lara Kastner

When I got on the plane to Copenhagen a few days later, I was expecting the meal at Noma to be comically bad, a fat pitch waiting to be smacked out of the park with a stout American bat. Noma sounds like a place that makes Moosewood seem like the Chicago Mercantile Exchange.

There are three major movements sweeping through the highest end of global gastronomy at the moment: the ecologically grounded localism of the foragers; the Rabelaisian excesses of the nose-to-tail crowd; and the exotic technologies of the Modernists, for whom the kitchen and the laboratory are one. Noma, whose chefs pick birch shoots in the woods before service; which often serves musk-ox tongue as the sole meat course; and which uses liquid nitrogen as casually as most kitchens use salt, stands at the precise nexus of the three—even the restaurant's biggest fans refer to Redzepi as the "whale whisperer," and descriptions of epic feasts tend more toward the cinematic than the gustatory.

In America, the forager chefs often come from the ranks of the overeducated drifters who grow spelt in their Brooklyn backyards, have secret ramps patches in Prospect Park and drive up to Fleisher's to take butchery classes even if they happen to be vegans. But in Europe, where many of the best restaurants tend to be proximate to the best ingredients, and where hunters have always shown up at the back door of even the fanciest kitchens with a brace of fat snipe or a sackful of wild morels, the confluence of foraging and cuisine has deep roots—Michel Bras and Alain Passard, who can draw as much beauty out of a parsnip as Monet did from a patch of water lilies, are among the most revered chefs in France. Modernist chefs are tinkerers, the guys who can McGyver a washtub, an aquarium pump and Aunt Ellie's old crockpot into a device that can poach a duck at precisely 56°C—the effects they go for are largely textural, and their techniques owe a lot to the scientists developing industrial food products for companies like PepsiCo and Kraft. Foraging and Modernism, like romantic and Modernist art, are opposites, seemingly incompatible.

I have typed the phrase "local, sustainable, organic, seasonal" into my computer so many times that I have been tempted to keep it as a save string, I have enjoyed sauces thickened with xanthan gum, and I am no stranger to the allures of foraging. But Noma, as the self-proclaimed standard-bearer of New Nordic Cuisine, actually has a manifesto, like that other Danish-rooted movement, Lars von Trier's Dogme 95. Redzepi's cookbook, "Noma: Time and Place in Nordic Cuisine," is possibly the least useful volume in the history of culinary literature, stuffed with severe photographs of wet forests, clumps of seaweed and the occasional plated composition of pork neck with bulrushes, as well as thoughtful essays about hobbyist sea-urchin divers and a Nordic culinary diary that includes the consumption of porpoise soup and raw puffin.

Inside Noma's spare dining room Photograph by Ditte Isager

When I get to the restaurant, which occupies a corner of a converted 18th-century warehouse now home to the Icelandic embassy as well as the provincial headquarters of Greenland and the Faroes, Redzepi himself shows me around the complex, which includes a bleached conference room with a view of the harbor, a staff room the size of a bowling alley, and a stand of weedy-looking plants growing in a frame Redzepi bought from some pot dealers in Christiania. He shows me a box of snapping langoustines, big as regulation footballs, for which the diver that catches them charges about $20 apiece. Vegetables are kept in crates out back—Redzepi doesn't go so far as to claim refrigeration saps carrots of their vitality, but you can tell that he thinks it does.

"When we started out here eight years ago," he says, "the idea was to use local products, like Alice Waters or Thomas Keller do, and integrate them into the cooking I already knew how to do. But it felt weird, replicating a dish from El Bulli, in whose kitchen I worked for so long, with Danish ingredients instead of Spanish ones. When I did a pot-au-feu with the ingredients we have here, it was still a pot-au-feu; it was still French. As a chef here, you discover wild nature, and you discover things in soil. This is not domestic monoculture. And through Noma, cooking has become the way I order my world. The food tells me how it wants to be cooked, through its own natural rhythms. We're just out of winter now, birch is green and beautiful and fragrant, but we're already thinking about the next one. It is hard work, but it is a good way to live life."

Down in the restaurant, seated at a plain wooden table on which is a vase holding a spray of wildflowers and some twigs, you chat with the waiter about whether you might like to try the wine pairings, or perhaps a flight of vegetable juices designed to go with the food. You notice an unusual seabird launching itself from a piling across the way.

It is then, more or less, that you discover that the first course has been sitting in front of you all this time—the gnarled twigs in the vase of wildflowers are sculpted from a kind of crunchy malt flatbread, dusted with powder made from dried beech shoots, ready to be plucked and munched like pretzel sticks. A second construction on the table, a box of mosses and pebbles that resembles a $120 arrangement from a Manhattan florist, includes puffs of spongy white moss set down like tumbleweeds. That's the edible part, although the potato-shaped sea pebbles look more like food. Next is a plate of empty, washed mussel shells glinting like blue steel in the afternoon sun. You dig among them for a minute until you discover the single sautéed mussel nestled in their midst—the crisp, trompe-l'oeil shell, you are told, is also edible, a kind of shiny cracker. The waiter hands you a young, raw leek whose root end has been dipped into a gauzy batter of beer and flour and then deep-fried—the effects of the heat vanish a couple of inches up the stalk—and you realize that so far you have seen neither a single utensil nor a single obviously edible plate of food.

Noma's signature dish, The Hen and the Egg Photograph by Ditte Isager

There are savory ebelskivers next, spherical Danish doughnuts with the ends of a small smoked fish poking out of each side like an arrow through Steve Martin's head; then chewy scraps of dried sea buckthorn leather with pickled rose petals, a smoked quail egg tucked into a larger ceramic egg filled with smoldering hay, and a slender fish-egg sandwich with fried chicken skin substituting for one of the slices of rye. Radishes are planted leaves-up in a terra-cotta flowerpot; you pluck them from the loamy malt-hazelnut soil and eat them leaves and all.

With a kind of reverence, a chef sets down a lidded mason jar filled with ice. Inside are tiny prawns from the fjord; after lumpfish roe, the translucent creatures are the second sign of Nordic spring. You open the jar, and the prawns stare up at you, barely moving, although when you pick one up, it wriggles like mad. You stare at it a moment, man against prawn, predator and prey, and when you pop it into your mouth you feel it go limp under your teeth all at once, its small life absorbed into your own.

The rest of the meal rushes by in a haze, but you remember dilled shrimp served on a landscape of baby beech shoots, sea urchin snow and sea pebbles frozen into ice; dried scallop chips draped over a composition of herbed grains and beech seeds; and raw beef scraped, not chopped, from the bone and covered with sorrel leaves to resemble the greenest two square inches of the forest floor. There was a purple carrot, two winters old, braised in butter until it resembled meat; and a loaf of bread wrapped in felt and served with goat butter and rendered lard—you may be reminded of the German artist Joseph Beuys, whose obsession with fat and felt was born when his plane was shot down over Crimea in World War II and the locals tended to his injuries by encasing him in those materials. A sea rock, seemingly too heavy to lift, is dappled with what looks like bird droppings but are actually dollops of pureed oysters dusted with dried seaweed; a roasted langoustine seems to crawl up the rock like a primordial trilobite. And then that egg.

If Alinea is Cirque du Soleil, Noma is Tristan and Isolde. The technology is the same, the airs and gels and water ovens, but in one case it is being used to dazzle, in the other, to enable a story to be told.

Noma chef René Redzepi Photograph by Ditte Isager

After lunch, we go out to a houseboat—not a fancy, picturesque one, more like a floating trailer-park thing—where Redzepi retires after lunch each day to experiment. It is yards from the restaurant—you can see it from a second-story window—but it seems miles away; a refuge. It smells out there, a rank bachelor-pad stink.

The houseboat was set up in 2007 as a nonprofit institution, a sort of think tank of Nordic cuisine. The houseboat crew has, for example, gone deep on the topic of local seaweed, of which there are 263 varieties in Danish waters. The houseboat has just received samples from the biggest dairy co-op in Denmark. The lab is working on a seaweed-flavored cheese for them. "Some of them taste like dirty beach," Redzepi says. "This one, called dulse, isn't bad." Redzepi smears a bit on a stone slab for me. The taste is round, a bit briny, with hints of black pepper and Parmesan cheese.

"But let's imagine eight years ago. If we were to eat today's menu then, we wouldn't have enjoyed it that much. We're trying to somehow reflect the flavor of our region, but what is it? Year by year, we are developing different answers. How often have we seen a product and tasted it in the field, only to discover the next day that its essence is gone? If you treat something well, whether it is a plant or an animal, it always seems to taste better. This is the important thing."

Has it made a difference, you wonder?

"Have we changed the diet of most Danes? Probably not. But if we ask ourselves what the famous Danish restaurants were cooking eight years ago, the answer would be French and Italian food. Now we're more focused on local food. Most of the important Danish restaurants now have a forager. You can find wild garlic shoots in supermarkets. You can buy birch syrup as well as maple. You can find sea buckthorn everywhere, even sea buckthorn–flavored yogurt."

"We're Protestants here. You probably saw 'Babette's Feast.' We ate one dish, we ate in silence, and life started afterwards. We ate to survive, we ate cheaply, and we ate mostly meat. Maybe what we're doing at Noma is futile. Maybe it's just a fling. But why not try? If you're going to cook, you've got to ask yourself why you want to cook."