Lunchbox Laboratory—Ballard's new experiment in premium hamburgers—was closed a week ago Monday. The handwritten sign on the door said that the Laboratory was not in operation today because the Professor—chef/owner Scott Simpson—was having surgery. He'd be back on Wednesday. Surgery! It was a case of both too much information (surgery plus restaurant does not equal something you want to think about) and too little (what KIND of surgery?! the mind perversely demands).

On Wednesday, while eating an enormous, dripping, and delicious lamb burger with havarti and basil aioli (and sweet-potato fries, and chocolate-mint shake—when in Rome, right?), I asked someone clearing dishes from one of the two communal tables about Monday's sign. (Lunchbox Laboratory is tiny; it promotes conversation and sharing—or, in some cases, oversharing.) Well, she said, the chef had gastric bypass surgery, and this was for "some complication."

"It was just in-and-out," she said, "some kind of an infection or a drainage thing."

Simpson's incredible— in the sense of not to be believed—story is a lot to digest. On the phone, he's extremely candid about how comfort food almost killed him. He's the chef who opened Blue Onion Bistro (upscale comfort food/kitsch in a former gas station on Roosevelt), then Fork on Capitol Hill (fine dining with comfort food fantasies like lobster corn dogs). Fork closed after six months amid Simpson's burgeoning physical and mental health problems—in the Seattle Times, he described holing up in his apartment and eating Domino's pizza for six months straight, ballooning up to 469 pounds.

Finally he went to Mexico and got gastric bypass surgery, a medical last-ditch effort for the obese: The capacity of the stomach is reduced by 90 percent via the creation of a pouch-stomach, made from a less-stretchy part of the original stomach. In Simpson's case, the pouch-stomach, he says, tore completely off inside him the day after the surgery. The doctors fixed it, but Simpson was in a coma for almost five months. "In November of 2006," he says, "they said, 'This guy's not gonna make it.'"

But he did make it, and now he's making giant burgers. These are burgers with the opposite of the usual problem: The patties are bigger than the (not small, Essential Baking Company) buns. It's your choice of eight or so different kinds of organic, ground-on-site meat; 15 different cheeses; 15 different house-made sauces; and a half-dozen more toppers (maple bacon, caramelized onions). Milkshakes, no-lumps-style, are more humanely apportioned in 400mL lab glassware. Then there are fries, twisty fries, sweet-potato fries, tater tots, a variation on onion rings, and macaroni and cheese du jour (often penne with blue cheese, though he's made a 15-cheese version—good, he says, but "a pain"). It's order at the counter, with kitschy stuff stuck all over the place, including a collection of vintage lunchboxes (Lassie looking noble, the Six Million Dollar Man using an entire tree to knock down some bad guys, "The Exciting World of Metrics"). Customers gape at the chalkboard of choices, stupefied. Lunchbox Laboratory's big streetside sign says "The Art and Science of American Comfort Food" with a drawing of a chef with a black eye.

Gastric bypass surgery works for overeaters like Antabuse works for alcoholics: If a bypass recipient eats too much, what's euphemistically described as "discomfort" results. Simpson says it's more like terrible pain: "It feels like somebody's stabbing me in the stomach." His portion size of his own wares: one-eighth of one burger. (He also still loves candy, portion size: one Godiva chocolate. Too much sugar is also terrible for gastric-bypass recipients, inducing "dumping syndrome," with cold sweats, extreme anxiety, stomach butterflies, then diarrhea.)

If Lunchbox Laboratory sounds like a masochistic enterprise for Simpson, he sounds genuinely happy. He can have a little bit—that eighth of a burger—and it gives him joy to cook "everything that I wish I could eat." (The burger-shack idea is also, he says, "something my mom always wanted me to do. This is for my mom. It's an homage.") If it sounds sadistic—like he wants you to have to get gastric-bypass surgery, too—he trusts you more than he could trust his former self. He pictures people coming in once a week or once a month. "Everything in balance," he says. The lack of that was, he says, his problem before. "You can't live life without having a little fun."

The burgers are exceptionally good. If you're amenable to the price point—$7–$9, cheese an extra $1.50, sides $3–$5, shakes $4, making it easy to spend more than $30 for two—you might very well create your new favorite burger at Lunchbox Laboratory. A suggestion for ordering: Keep it simple. The stronger cheeses and sauces can overpower the fine flavor of the meats (like buffalo, prime rib, and "dork," or duck/pork). In this (possibly unique) instance, bacon is overkill. And one side to share is more than plenty. Other sandwiches sometimes featured as specials look great, like a massive cheesesteak leaking off its serving platter of a midsized wood cutting board. (Overheard: "I want to finish it, but I don't know if I can.")

Simpson's latest surgery went fine—they did, he said, an endoscopy and removed a little metal straw that the doctors in Mexico improvised during his complications to keep liquid from hitting his stomach. It was an in-and-out thing. Say hi to him at Lunchbox Laboratory. He's lucky to be there.