On the Italian island of Sardinia, local diners throw invitation-only get-togethers where the main attraction is casu marzu, a pecorino that can't be purchased in any store. It is matured in blocks the size of a human head and spread on thin slices of folded bread.

The problem that faces the neophyte is not picking up the cheese but keeping it down: casu marzu is only considered mature enough when it is infested with thousands of transparent maggots. What's more, the fly larvae must be living, as dead maggots are a sure sign the cheese is too rotten to eat. Sardinians advise neophytes to hold a hand over the sandwich to prevent the vermin from leaping into their eyes.

In the Landes region of Gascony, aging poachers trap a protected songbird in nets, fatten it on millet in darkened cages until it is four times its original size, then drown it in Armagnac. The ortolan, also known as the bunting, is eaten at clandestine dinners by gastronomes who suck the bird's piping hot innards through its rectum.

Story continues below advertisement

The late French president François Mitterrand, when he learned he was dying of cancer, invited 30 friends to a New Year's feast of oysters, foie gras, capon, and a plate of ortolans - a dish illegal for the hoi polloi, but, following the age-old double standard that exempts rulers from their own rulings, permissible for the elite.

The tiny birds, after being roasted at high heat for five minutes, are traditionally eaten whole, bones and all, with one's head hidden beneath a white cloth napkin. Some believe the custom was conceived to prevent the grease, bone fragments, and saliva from the feeding frenzy from splattering one's fellow diners. Others say it is intended to keep what you are doing hidden from God.

Almost every European nation boasts some abstruse gastronomic tradition that its neighbours find unsanitary, incomprehensible, or just plain disgusting. Germans enjoy Ochsenmaul-Salat, a salad made from the thinly sliced cartilage of cow's jaws.

Scandinavians have a marked penchant for putrefying seafood: Icelanders are fond of hakarl - the poisonous Greenland shark - whose flesh is buried two metres underground for several weeks, until it has fermented and lost its toxic charge of cyanic acid; only then can it be dug up and gnawed, like ammonia-scented beef jerky, between gulps of aquavit. (The British like to believe they are above such nonsense, even as they relish another helping of spotted dick, pork scratchings and Scotch eggs, preferably drowned in brown sauce.)

For the past 10 years, I've limited my flesh intake to the occasional seafood meal, but when I'm feeling adventurous, I'm willing to try an unfamiliar specialty, even a blatantly carnivorous one - though I tend to draw the line at the powdered horns of rhinos and the flesh of panda bears and other endangered species. I'm particularly open to novel meat-eating experiences in Europe, where by law livestock can't be fed genetically modified organisms or animal protein, or be injected with growth hormones.

In January, 2002, the European Union set up the Food Safety Authority in Brussels (now headquartered in Parma, Italy) as a kind of supranational, science-based organization to oversee the safety of the food supply. I feared the birth of a powerful continent-wide bureaucracy might mean the days of roasted French game birds, Scandinavian whale jerky, Italian maggot cheese - and everything else that made eating in Europe an adventure - might be numbered.

Which is why I was standing at a counter in Madrid, trying to persuade the bartender to give me the address of a restaurant - or tapas bar, or even a market stall - that would sell me a plate of bull's testicles. I figured that if any country in Europe was up to resisting the ambient healthism of the EU, it would be lusty, paradoxical, devil-may-care Spain. And if there was any city in Spain that didn't give a damn about bureaucrats from Brussels, it would be proudly provincial Madrid, where you can still spew smoke from a black-tobacco Ducado toward the ranks of dusty, fluorescent-lit hams dangling from the rafters. And if there was any bar in Madrid where they would be able to tip me off about sketchy carnivorous delights, it would be La Torre del Oro, that slightly psychotic temple of tauromachy in the Plaza Mayor, Madrid's great central square.

Story continues below advertisement

I was sipping a Manzanilla at the bar, beneath the mounted head of Barbero, a bull that had, according to the plaque over my head, weighed 616 kilograms when it was in the prime of its short life. The waiters at La Torre del Oro, nattily attired in black-lapelled vests and green bow ties, had maintained the gruff good humour of their native Andalusia. I had developed a nodding acquaintance with one of them, a proud Sevillian who squinted at the world through thick glasses, apparently always half-amused by his clientele.

"It's hard to find criadillas these days," he said as he handed me a demitasse of velvety, smoky gazpacho. "The best place to look is in the markets. It's still something you only find in hidden restaurants, especially since the whole mad-cow problem. But they are delicious. And because criadillas taste so good, people are ready to pay a lot of money for them."

Criadillas is the Spanish word for an animal's testicles - at least once they've been cooked. Downing the cojones of a freshly slaughtered bull has long been seen as a way of proving one's machismo. For years, people flocked to restaurants around bullrings in the corrida season to feast on what they believed was the adrenaline-impregnated flesh of animals they had just seen slain.

At the height of la vaca loca - the mad-cow outbreak - the carcasses of bulls killed in Spanish rings were burned rather than butchered, and even the bloody ears and tails, traditionally tossed by the victorious torero into the crowd, were replaced by fakes for fear of contagion. Since 2001, the abattoir at the back of Madrid's Las Ventas bullring has officially been closed. I was beginning to think that, given the recent history of food scares, tracking down real criadillas might prove impossible.

I decided it was time to enlist the aid of a genuine Madrileno in my hunt for criadillas. I phoned up Chipi, whose number a Spanish mathematician I had met in Montreal had given me. If we were going to find criadillas anywhere, Chipi told me, it would be in the working-class neighbourhood of Lavapies, whose brick streets, between ochre walls of balconied walk-ups, seemed to trickle downhill from the Plaza Tirso de Molina.

"You have to look for places where the menus are written on the walls with white paint," Chipi said.

Story continues below advertisement

Opening the door to the Bar Restaurante EI Jamon, he peered inside and said, "This one looks pretty good." Sure enough, a hand-lettered sign on the wall above the bar read, " Criadillas, 4 € 50."

We took a table in the back, where a reality show played on a flickering TV set. Chipi looked appreciatively at the layer of sawdust and cigarette butts on the floor. For him, this was another good sign.

The waitress spread paper over the tablecloth, plunked down bread, a bottle of fizzy lemonade, and a red wine called El Barrio de Lavapies, whose label showed not a rural vineyard but laundry hanging out to dry on a balcony. Chipi put his palm against the bottle and grimaced. "Cold," he said. "Usually that means it's not very good."

The waitress reappeared to take our order.

" Tomare criadillas!" I practically shouted.

"I'm sorry," she replied, "we are sold out this afternoon."

Story continues below advertisement

I must have looked crestfallen. Chipi said, "Look, they have entresijos and gallinejas. Those are pretty extreme."

Not the same, I pouted, agreeing nonetheless. The waitress brought us a plate of oily, deep-fried organs. The gallinejas were lamb intestines, fatty, crispy, and bunched into tubes so they looked like the spidery-knuckled fingers of some malevolent alien. The entresijos - well, they came from the inside of a lamb, we knew that. Chipi was pretty sure they were parts of the respiratory tract. Glistening with grease, they bulged with strange pockets and sacs.

Like all viscera, I was discovering, they had a strong odour of the barnyard and resisted the teeth mightily. I managed to choke down most of mine by sandwiching them between hunks of bread, and washing the fatty mess down with huge gulps of Lavapies' finest red.

After the meal, we wandered the streets, a little stunned, each in his own bubble of grease. Through his torpor, Chipi suddenly brightened. "We might be able to find criadillas here. . ."

We stopped outside the Bar Mariano, on the Plaza Tirso de Molina. The skinned head of a lamb, topped with a wreath of parsley, glared blankly at us from the window, like a figurine from some Flemish anatomist's studio.

Inside, the fluorescent lighting was maximum wattage, the sawdust was thick on the floor, and the fans following the Real Madrid soccer match were deafening. We found a small table and scanned the menu for criadillas, in vain.

Story continues below advertisement

"You're out of luck again," sighed Chipi. "But they have zarajos! When it comes to all this organ stuff, they're the ones I like best."

The waiter brought a plate of five, accompanied by a quarter of a lemon. Once again we were eating lambs' intestines, but these ones were artfully wrapped around two vine shoots laid crosswise, so they formed a circular mass of rubbery twine. It brought to mind some toy from the Great Depression, a homemade bouncy ball improvised by Spanky and Our Gang.

Chipi crossed his eyes as he unravelled a zarajo with his incisors; when he managed to nip off a piece, it actually rebounded against his chest like an elastic band, splattering us with grease.

I managed to get through one before pushing the plate away. I was beginning to wonder about this whole matter of eating headcheese, chitterlings, sweetbreads. No matter how you dressed it up, it was still tongues swallowing tongues, innards digesting innards, intestines slipping through intestines.

Again we wandered the streets in a daze, checking out menus. A block toward the Plaza Mayor, Chipi looked thunderstruck. "Of course!" He led me, practically at a run, to the narrow red-and-green façade of a restaurant. "This is where I had criadillas!" he said. "The Casa Rodriguez!" The metal curtains had already been pulled over the door for the night.

By then, Chipi had to run for the last train to his suburb, but as he trotted away, the Tintin of Tapas shouted over his shoulder, "Just go there for lunch tomorrow! They'll have your balls for sure!"

Story continues below advertisement

Finally, my scavenger hunt had come to an end. It was lunchtime at Casa Rodriguez, and sitting before me, in all its fleshy glory, was the long-sought plate of criadillas. I'd heard bull's balls are often baked into a pie, empanada-style, but here the dish took the form of a thick gravy, served with spicy guindilla chilies and slivers of garlic fried soft, all swimming in an earthenware bowl. A dozen suspiciously rounded lumps, each about an inch long, were distributed throughout the sauce. I took a preparatory swig of tongue-rasping red wine to lubricate my throat and dug in.

At first, what predominated was the barnyard taste I had come to associate with all organ meats. But, after a couple more gulps of wine, my palate overcame its suspicion. The meat was soft, almost fluffy, but not at all chewy. The sauce had a bacony flavour, and eventually the irresistible blend of garlic and chilies overpowered everything, turning the suspicious lumps into just another source of protein. I ate five of them. Then 10. Then I sopped up the sauce with my bread and downed the rest of the wine.

I was cleaning my teeth with a toothpick, feeling a real sense of accomplishment - perhaps even some increased virility - when the owner came up. He had jowly cheeks, beagle folds under his brown eyes: His was the face of a sad clown. I deduced from the cries of a group of boisterous municipal street cleaners in sleeveless T-shirts that his name was Jose.

Jose folded his arms over his green blazer and eyed me sullenly. "We don't get many foreigners here," he said. "What did you think of our criadillas?"

" Excelente!" I replied. "But I didn't think they'd be so small. The ones I saw at Maravillas market were very big!" I used both hands to describe an ostrich-egg-sized oval.

"Those were criadillas de toro, senor. They are different. These are criadillas de cerdo."

In other words, pig's balls. No wonder they had been so small. I suddenly felt quite ill.

"We usually serve the other ones during the bullfighting season." He pointed to a calendar. "It is October now. You might consider returning in April."

Well, that explained a lot. I'd missed the end of the season by a week. Trying my best to maintain my sangfroid - er, sangre fria - I assured him I would do just that.

The reality was, though, that it was time for me to move on, and I would be swearing off meat once again. It wasn't so much that I was getting fat or feeling unfit; nor had I suffered from a single bout of indigestion in Spain. It was just that, as much as I believed in my absolute freedom to choose my own poison with impunity, I also valued my freedom not to be poisoned against my knowledge or will.

I was returning to North America, where I no longer had any idea what kind of pathogens were present in supermarket ground round, which now has to be labelled as if it were toxic waste. In Europe, I was happy to feast on lamb's intestines and bull's balls. But I had absolutely no desire to expose myself to the growth-hormone-injected, GM-grain-fed, salmonella- and E. coli-infested product that now passes for the American hamburger.

I may be decadent, but I'm not stupid.

Special to The Globe and Mail