McMillan and Morin are not the first high-profile chefs to get sober in recent memory. Michael Solomonov, who owns Zahav, the acclaimed Israeli restaurant in Philadelphia, began treatment for crack-cocaine addiction and alcoholism a decade ago. Sean Brock, best known for the restaurant Husk, in Charleston, wrote last April about quitting drinking and taking up a new “self-care” regimen that included meditation and Reiki. Brock and Solomonov are just two of many chefs who now serve nonalcoholic cocktails at their restaurants. In “The Rise of the Sober Chef,” a First We Feast story from 2015, Solomonov noted that admitting you’re an alcoholic “is less of a taboo than it was ten years ago—even in the kitchen.”

Before McMillan and Morin gave up drinking, Joe Beef was an occasionally volatile and abusive work environment; they are adamant that sobriety has made them more responsible bosses. Both are evangelists by nature. Where they once promoted unbridled hedonism, they’ve now become unlikely crusaders against the excesses of restaurant culture. McMillan said, “I believe clearly now that you can make a decision to go into the service industry and have a healthy life, a happy life, as a waiter, a sommelier, or a cook.”

McMillan and Morin grew up in Montreal, not far from each other, and both developed an early interest in French cooking. Morin watched Jacques Pépin and Julia Child on TV; McMillan recalls his mother bringing home a book by the Lyonnaise chef Paul Bocuse. After high school, both began working in restaurants, and, later, attended cooking school. At the time, there was little glamour in being a chef. “We went into cooking like you go into plumbing or electricity,” McMillan said.

They didn’t know each other well until 1999, when they found themselves working together at the Globe, a restaurant and supper club in downtown Montreal. McMillan was the chef de cuisine and Morin was his sous chef. The Globe had been an excellent French restaurant, they told me, but it began catering to a late-night crowd who cared little about the food. “They dressed the waitresses like sluts, in little pink tight dresses,” McMillan said. “They did bottle service. The restaurant was frequented by the Mafia and motorcycle gangs and drug dealers, vodka drinkers, d.j. culture. Sodom and Gomorrah.” In 2004, Morin took over the kitchen while McMillan oversaw the opening of a sister restaurant, Rosalie. McMillan, overworked and drinking too much, had what he has called a “little breakdown.” “We were so burned out,” Morin said. “We were both on antidepressants.” They wondered if they should get out of the industry altogether.

At the time, modernist chefs like Ferran Adrià, in Spain, and Charlie Trotter, in Chicago, were in vogue, but McMillan and Morin retained their passion for traditional French food. After shifts at the Globe, they ate at L’Express, one of Montreal’s few remaining old-school bistros, where the ceilings are painted yellow to match stains from the cigarette smoke that once filled the dining room, and each meal begins with a server delivering to the table a jar of cornichons and a pot of mustard. McMillan and Morin still consider it a perfect restaurant. They also admired a new generation of chefs who’d opened small, idiosyncratic restaurants in the U.S. and in Canada: Gabrielle Hamilton, who had, Morin said, the temerity to put Triscuits on the menu at her tiny New York restaurant, Prune; Martin Picard, whose Montreal tavern, Au Pied de Cochon, served the kind of snout-to-tail cooking that was gaining popularity at the time, with a Québécois spin, including a famous foie-gras poutine.

On their days off, McMillan and Morin often hung out in Little Burgundy—then a backwater neighborhood of greasy spoons, thrift shops, and Art Deco buildings like the home of Atwater, one of Montreal’s sprawling indoor markets. One morning, the owner of a café on Notre-Dame Street West mentioned that he was closing his business, and offered them cheap rent on the dingy space. McMillan, Morin, and Allison Cunningham, a server at the Globe (who later married Morin), decided to go in on it together. They fixed up the twenty-six-seat dining room, putting in wainscotting and a bar made from a farmhouse floor. Out back, they planted a garden and installed a smoker. They named the restaurant after Charles (Joe Beef) McKiernan, the proprietor of a rowdy nineteenth-century Montreal tavern.

McMillan and Morin served raw seafood and French classics such as Dover-sole meunière and pâté en croûte. Morin devised a creamy, lardon-studded lobster spaghetti, now a Joe Beef staple. They found a supplier of horsemeat, an ingredient that they describe in their first cookbook, “The Art of Living According to Joe Beef,” as “the great divide between Anglophone and Francophone.” There was an intimacy to the dining room: McMillan shucked oysters at the bar and kibbitzed with customers. The occasional rude or disruptive guest was invited to leave. Within six months, the restaurant was booking tables a month in advance.

McMillan and Morin attribute much of their success to the support of Chang and Bourdain. In a 2013 episode of his TV series “Parts Unknown,” Bourdain spent a sybaritic few days with McMillan and Morin in and around Montreal. They staged a six-course meal in an ice-fishing shack on the frozen St. Lawrence River. It included Glacier Bay and Beausoleil oysters, oxtail consommé over foie gras, chilled lobster à la Parisienne with shaved truffles, wild hare in a sauce of its own blood, Époisses cheese smeared on bread, and a layer cake called a Marjolaine. They smoked Cuban cigars and drank white Burgundy and Chartreuse. Later in the episode, on a trip to Martin Picard’s Cabane à Sucre Au Pied de Cochon, outside Montreal, Morin opened a bottle of sparkling wine with a hammer.

McMillan’s greatest passion, apart from French cooking, was natural wine, a movement—until recently based almost entirely in France—to produce wines using organic or biodynamically grown grapes, no additives, and minimal processing. In 2015, he helped Vanya Filipovic, Joe Beef’s wine director and a partner in Le Vin Papillon, start an import business, turning his restaurants into a hub of natural wine in North America. But his oenophilia became a cover for his accelerating alcoholism. When McMillan first went to rehab, he said, he’d look at other addicts and think, “Oh, no, no, I’m not like you losers. I have a natural-wine problem.”

McMillan made intermittent efforts to drink less and to go to the gym. In 2013, he had gastric bypass surgery. He lost a hundred and eighty pounds in the following years, but he continued to drink heavily. Max Campbell, a bartender and server who has worked at Joe Beef for more than a decade, told me that, each night, when McMillan came into the restaurant, “I’d open one, two bottles, three bottles, I don’t know.” McMillan would make the rounds in the dining room, pouring wine, Calvados, and champagne for customers and for himself. Sometimes Campbell had to make excuses for McMillan’s drunken behavior; one night, he drove him home in McMillan’s own car. Meredith Erickson told me, “David changed from being the guy who everyone wanted to circle around, and listen to the stories, to a guy where everyone was just, like, ‘I’m feeling really uncomfortable, because you’re not acting like the guy we love right now.’ ”

Several current and former Joe Beef employees told me that they’d felt pressure to drink. After hours, McMillan would herd staff members to the bar across the street and buy them beers and shots of whiskey. In the summer, Campbell said, “we’d all sit outside on the terrace and we’d drink beer until the keg ran out.” Emily Ekelund, a former employee, started working as a busser at Joe Beef in 2011, and was eventually promoted to bartender. In 2014, she left the job to focus on getting sober. When she returned, a year and a half later, to work at Le Vin Papillon, it was with certain stipulations—she’d no longer close the bar or work past midnight. “I needed to get myself out of that environment in order to stop drinking,” she said.

McMillan and Morin say that sobriety has made them more responsible bosses. Photograph by Alexi Hobbs for The New Yorker

According to a 2015 report by the Substance Abuse and Mental Health Services Administration, the food-service and hospitality sectors have among the highest rates of alcohol and drug use of any industry. Morin said that he thinks drinking is responsible for most of “the anger and the pressure and the abuse” in professional kitchens. As a young chef, he witnessed several bad fights in kitchens, including one that had to be broken up by the police. McMillan told me, “Everybody that I worked for, all my mentors, were screamers. I’ve been hit multiple times in the kitchen.” Morin recalled once throwing a pan of bacon onto the floor after a line cook accidentally tossed out fresh fish. McMillan said, “Joe Beef is the nicest restaurant I’ve ever worked at. But have I screamed at people? Yes, I have. Have I punched people? Fucking yeah. I’ve never hit a woman.”