This weekend, 10,000 people will descend on Los Angeles—and it’s not because President Obama’s in town. They’re there for one thing only: grilled cheese. The Grilled Cheese Invitational, now in its eighth year, will take place on Saturday, April 23, in downtown Los Angeles. The invitational is both an attraction for food lovers and a blood sport, as 300 chefs from around the country will compete for prizes for the best grilled cheese.

Both professional and amateur chefs will face off in four categories: “Love, American Style,” in which competitors use only classic white bread, orange cheese, and butter, but is the most difficult category to win; “Missionary,” with any type of bread, butter, or cheese; “Kama Sutra,” in which chefs are allowed to use additional ingredients like bacon; and “Honey Pot,” a category for desserts, such as a grilled banana bread with ricotta cheese.

The sandwiches are separated into categories, officials say, to prevent an unassuming cheese-and-bread melt from going up against a heaping mountain of cheese and meats. According to invitational veteran Alex Brown, of the Hot Knives Kitchen, winning is about keeping it simple. “The bacon wave is finally slowing down,” he says. “The best advice is to use really good stuff and make it not overwrought conceptually. People get too wild-eyed about making sandwiches that have a lot of crap in them. Use good cheese, and use good butter, and use good bread. And then you will be victorious.”

The idea for the invitational came in 2003, when Tim Walker, who now calls himself the “Chief Instigator and Founder,” invited friends to make their favorite grilled cheese sandwiches at a party in his loft downtown. It became an annual tradition, and each year it grew—until it eventually got so big it took over a city park, enticed sponsorship, and attracted national attention. Now, “It’s the American Idol for cheese,” Walker says. Still, he has big dreams: “I’d like this to displace the Super Bowl in television ratings. Or take it to the Coliseum. We could hang a big grilled cheese out of a helicopter and cook it over the Olympic flame.”

Indeed, for hopeful fans, the 2010 Grilled Cheese Invitational was more reminiscent of American Idol’s city-wide auditions, with mile-long lines, funny costumes (such as grilled-cheese chaps) and a slim chance at actually getting before the judges and snagging a morsel of grilled cheese. One thing is for sure: the invitational requires patience for crowds and loud music, a high tolerance for lactose—and a deep passion for grilled cheese.

The competitors and vendors are themselves a passionate bunch, many of whom have shaped hobbies and careers around grilled cheese. Take, for example, Michael Davidson, a 28-year-old scientist developing blood-screening products for Human Papillomavirus at Roche, who has, in his spare time, developed a cult following around California as the “Grilled Cheez Guy.” (Davidson’s secret weapon is a brick wrapped in tinfoil to press the grilled cheese, and he’ll compete for the first time this year as a professional.) Then there is dark-horse Cecilia Fabulich, a retired grandmother from Marina del Rey who took first place in the Judges’ Trophy last year; Dave Danhi from the formidable Grilled Cheese Truck with it’s 36,000 Twitter followers and a tough-to-beat “Cheesy Mac and Rib”; Eric Greenspan, a well-known chef at The Foundry restaurant who plans to open a grilled-cheese only store next to his Hollywood restaurant next year, and Evan George and Alex Brown, Hot Knives’ “eccentric vegetarian food bloggers,” who have co-authored a book, Salad Daze, which is due out next fall. (George and Brown have competed in numerous invitationals, and call their secret weapon their “cheese arsenal,” as Brown is a Los-Angeles based importer of European cheeses.)

“Originally, everyone thought I was the crazy one for starting this up,” Walker, the founder, says. “But now we have 10,000 people participating. I’m not the crazy one—we’re all crazy together. As adults in life, we don’t have a lot of opportunity to have fun like this.”

“It’s the American Idol for cheese,” Tim Walker, the invitational’s founder, says.

Photo Above:

The sandwiches above are the grilled cheeses of six competitors in the 2011 Grilled Cheese Invitational. They were photographed by Misha Gravenor for Newsweek/ The Daily Beast in Los Angeles. From Top: (1) “The Mousetrap,” with sourdough bread, Tillamook cheddar, havarti and Monterey Jack, by Heidi Gibson and Nathan Pollak at the American Grilled Cheese Kitchen in San Francisco. (2) A sandwich with gruyere, parmesan, and Belgian-beer braised onions on brioche, by Evan George and Alex Brown, from the Hot Knives Kitchen. (3) A grilled cheese by Cecilia Fabulich, with aged cheddar and white bread. (4) The Foundry’s grilled cheese, by Eric Greenspan, which includes taleggio, oven-roasted tomatoes, braised short-rib and raisin bread; (5) A sandwich of pain au levain, fresh mozzarella, white and orange cheddar cheese, by Michael Davidson, the Grilled Cheez Guy. (6) The “Cheesy Mac and Rib,” with pulled pork, mac n’ cheese, and caramelized onions, from the Grilled Cheese Truck, by Dave Dahni.

Isabel Wilkinson is an assistant editor at The Daily Beast based in Los Angeles.