Forget about the Summer Olympics. Those with an appetite for nail-biting competition need look no farther than the blocks surrounding 7th St. and Marquette Av. S. in downtown Minneapolis. Starting most weekdays at about 10 minutes before the magic hour of 9 a.m., a parade of brightly painted food trucks engage in a highly choreographed race along the area's grid of traffic-clogged one-way streets. The prize? A parking space.

The competition is fierce. Arrive even as little as a minute or two too early, and risk a substantial fine and the loss of that coveted spot. Arrive too late, and miss a potentially lucrative berth in what has become downtown's unofficial outdoor food court.

A 20-foot vehicle affectionately known as "Big Red" is often in the mix. It belongs to Lisa Carlson and Carrie Summer. When these two pedigreed chefs started cooking in a cramped trailer in 2008, there was just one other licensed food truck operating in Minneapolis. Today there are dozens, and surely more are on the way. All owe a debt to Carlson and Summer and the pioneering venture they call Chef Shack.

"Before Minneapolis became known -- or even functioned -- as a great street-food city, Chef Shack was dishing doughnuts," said John T. Edge in an interview. He's the author of "The Food Truck Cookbook," an insightful, coast-to-coast chronicle of the nation's culinary movement of the moment. "They're as good as any truck out there. They're not surfing trends, they're skewing their own way and making highly personal food. That's why their cooking shines bright. I admire the heck out of them."

Carlson is a Brooklyn Center native, and Summer grew up in Rochester. Both spent time working for and learning from an impressive constellation of starry chefs in New York, San Francisco and London, including Gray Kunz, Daniel Humm, Jean-Georges Vongerichten and Masaharu Morimoto.

They've been a couple for 11 years, and naturally, the two 44-year-olds met in a kitchen, when Carlson, who was running an Uptown Minneapolis restaurant, hired Summer. Turns out they work well together, in a finish-each-other's sentence kind of way, and their slightly overlapping skill sets -- Carlson is Chef Shack's chef du cuisine, and Summer, the company motorhead, handles pastry and manages the business -- are more than complementary. "Between the two of us, we divide and conquer," said Carlson with a laugh.

No kidding. Chef Shack was born at the Mill City Farmers Market. It started with a suggestion from their boss and one of the market's driving forces, Spoonriver owner Brenda Langton. Tapping into her lifelong obsession with doughnuts, Summer immersed herself in research, bought a mini-doughnut machine from Lil' Orbits in Plymouth (she borrowed the money from Carlson) and, through a tenacious trial-and-error period, zeroed in on an all-organic formula for what became an instant Chef Shack trademark: diminutive, puffy, melt-in-your-mouth doughnuts, their golden exteriors twinkling with sugar and a nose-tickling blend of cardamom, ginger and nutmeg. It is impossible to eat just one; blindly consuming a fist-size bag is deceptively easy.

They called their stand Urban Donut -- in a counter-programming move, Carlson contributed a cool, refreshing gazpacho -- and it's not an exaggeration to note that word spread like wildfire (it didn't hurt that the Chef Shack-ers have been social media savants from the get-go). When the next spring arrived, they traded up to a trailer that they christened Chef Shack. With a newly expanded menu, they were off and running, literally.

"At one point, almost the entire cooler at Spoonriver was full with containers labeled 'Chef Shack,'" said Carlson. "Brenda came in and said, 'I think it's time you got your own kitchen.'"

Six years, countless 17-hour days and two more vehicles later (including an adorable 1970 International -- the 1966 Mustang GT convertible of the food-truck set), Summer estimates that she's made over a million doughnuts. She orders her specially formulated, certified organic doughnut mix in 50-pound bags, 20 bags at a time.

"I never tire of making doughnuts," said Summer. "When I'm 70, I can see myself driving the truck around, making a living making doughnuts."

With downtown street-food licensing a few years into the future, at least in downtown Minneapolis, Summer and Carlson grew their business -- and eventually left the security of their full-time jobs -- by tapping into a familiar audience, this time at the Kingfield Farmers Market. Chef Shack wasn't an original Kingfield vendor, but they quickly became a hugely influential one.

"By the time they came along, we were already starting to show some real growth and we were feeling good about it," said board chair David Brauer. "We had other vendors in the past who had been draws, but we've never had a draw like them. They were the linchpin to taking us to the next level."

In 2011, after 10 years at 43rd and Nicollet, Kingfield turned its attention westward, adding a companion market at 49th and Chowen in the Fulton neighborhood, and Chef Shack was a key player from the get-go. "The fact that they said 'yes' did a lot to reassure us as we took that major step into a brand-new venture," Brauer said.

Cooking outside the box

The expertise, discipline and ingredient-driven mentality that is part and parcel of the duo's fine-dining background is what sets Chef Shack apart from the vast majority of their food truck brethren. That, along with an allergy to clichs and gimmicks, as well as an obsessive attention to detail that routinely manifests itself in complex flavor profiles, no simple feat while also emphasizing portability, affordability and speed.

After doughnuts, the truck's bestseller is a truly remarkable burger of lean, flavorful, pasture-raised bison. It's an insanely delicious formula: a medium-rare patty brushed with a beef demi-glace and dressed with lettuce, tomato, a runny egg and a slab of Cheddar or pepperjack cheese, all inside a tender toasted brioche bun. In the past week, Carlson has been subbing out the egg and cheese for a street food rarity: seared foie gras, its blatant richness undercut by a swipe of tart yuzu marmalade.

"We want to give a little luxury to people on the street," said Summer.

There's more. Braised beef tongue is the foundation for a spectacular taco. Pulled pork, cooked low and slow until the meat teeters towards mouth-melting consistency, is the centerpiece of an awe-inspiring plate of nachos. Every bite of a tempura-battered soft-shell crab sandwich transports taste buds directly to the beach.

In the off season, the couple travel. Extensively. "That's how Chef Shack got started," said Summer. "When we're traveling, we experience all this incredible street food, and we wanted to bring those flavors here. Life happens on the street."

One of many forays into Southeast Asia inspired another simple but not simplistic sandwich: pork loaf perfumed with ginger, garlic, cilantro and lemongrass. Each slice is seared on the grill until it's tantalizingly caramelized, then topped by a sweet-sour face-off between a coconut-ginger sauce and a crunchy slaw of pickled purple cabbage.

There's a reason why vegetarians and vegans flock to Chef Shack. A taco of pured sweet potatoes, black beans and cilantro is splashed with Carlson's riff on salsa, usually bursting with tomatoes, corn, peppers, tomatillos, or all of the above. A flavor-packed watermelon gazpacho impresses for its hot-off-the-farm vibrancy. Carlson has a knack for colorful, hyper-seasonal salads, deftly combining an ever-fluid blend of just-picked greens, roasted and pickled vegetables, tender grains and inventive vinaigrettes. And Summer's carefully executed ice creams stand up to the work of any local premium maker.

Credit where credit is due

A safe assumption is that new food trucks keep popping up because Carlson and Summer make it look easy. "People see our success and assume that it will happen to them, but there are a lot of challenges that go on behind closed doors," said Summer. "The first advice that we give anyone who asks is, 'Don't quit your day job.'"

Easy is about the last word that describes this particular corner of the hospitality industry. Put aside the difficulties of cautiously nurturing a business on a pay-as-you-go basis, since banks weren't interested ("They were like, 'Absolutely not,'" said Carlson). Ignore cooking with four other people in a hot 7-by-10-foot Chevy van. Forget about navigating undependable weather, or predicting the demands and the size of a crowd, or dealing with flat tires and other frequent mechanical breakdowns. All are a cakewalk, relatively speaking.

"The biggest and most exhausting challenge is having to put your whole show on the road," said Carlson. "It's setting up a restaurant and then taking it down, every day."

Still, from the outside peering in, the herculean effort doesn't show. What does come across is the couple's innate generosity. For starters, Carlson and Summer use their purchasing power to support their fellow farmers-market vendors. "They're also big boosters of the food truck scene, of the people that others might think of as competitors," said Brauer. "The fact that they're willing to promote their 'competitors' is another mark of class for them."

Erica Strait concurs. After working for Chef Shack, she launched Foxy Falafel, first as a farmers market stand, and later as a food truck. Her bricks-and-mortar restaurant of the same name opened this month in St. Paul.

"They're like my big sisters," said Strait. "They have always been there for me; they always have their eyeballs out for me. It's unconditional support. They don't want anything back. They're just excited to see you become successful."

Booming business

The growth continues. After several years in a shared commercial facility, Carlson and Summer and their 12 employees moved into their own spacious, well-equipped commissary kitchen in May in south Minneapolis. Even bigger news: The couple are opening a casual, weekend-only bistro this fall in Bay City, Wis., a sleepy Lake Pepin town just south of Red Wing, Minn.

Summer describes their plans for Chef Shack at Bay City as "very approachable bistro food, and an expression of who we are," she said. "I'm coining the phrase, 'Wild-grown heritage cookery from the valley.'"

Rest assured, urban Chef Shack lovers, it's business as usual in the city. The distinctive red trucks will keep vying for those premium parking spots, and Carlson and Summer will continue feeding their loyal customers and welcoming new food truckers into the fold.

"I love it when another chef in town gets a truck, and we have to step it up even more," said Carlson. "That's good for everyone."

Follow Rick Nelson on Twitter: @RickNelsonStrib