On a recent June afternoon at Jean Georges restaurant in New York, it didn't seem to matter that the namesake chef was off dealing with legal issues rather than in the kitchen. The food and service were up to par, and lunchtime diners cooed over signature dishes like delicately scrambled eggs dusted with caviar and a roving cart of pastel-colored homemade marshmallows.

It will likely become more difficult for Jean-Georges Vongerichten to finesse the disappearing act. Last year the Michelin-starred chef, who has seven eateries in New York alone, inked a deal with Starwood Hotels to expand his restaurant empire to gargantuan proportions. High-profile chefs have been partnering up with luxury hotels like mad—Gordon Ramsay has locations at the London hotels in New York and West Hollywood; Masaharu Morimoto will open a sushi bar at the Boca Raton Resort & Club in Florida this fall; Alfred Portale is establishing a Gotham Steak at the Fontainebleau Miami Beach—but Vongerichten plans to trump them all.

The agreement, brokered by $2 billion private-equity firm Catterton Partners, calls for between 30 and 50 Jean-Georges-branded hotel restaurants within five years. Already, branches of Vongerichten's Spice Market have opened at W hotels in Atlanta, Istanbul, and Doha, Qatar. There will be a total of 10 locations at Starwood brands, including the St. Regis and Westin, by the end of the year.

"I like the business part," says Vongerichten, who has ambitions to run his own hotel one day. "I know this can't be it. I have too many ideas, too many dreams."

"This" is a constellation of 18 respected restaurants—including one of only three in New York to earn three Michelin stars—and four cookbooks under his belt. So far he has been able to run it all without publicly being spread too thin. But the question is whether Vongerichten can expand his empire so ambitiously and maintain the quality, creativity, and level of service that made the Starwood plan possible in the first place.

Vongerichten's new outposts are not Morton's steak houses, with identical menus and identities. The concepts include Spice Market, J&G Steakhouse, Market by Jean-Georges, and a resort restaurant, all high-end spots with constantly changing menus and complicated recipes. Meanwhile, Catterton's previous restaurant experience is with casual eateries like the Chinese chain P.F. Chang's.

Ambition can be a poison pill for high-end chefs. With multiple concepts, they run the risk of losing cachet among critics and diners. Thomas Keller and Eric Ripert, the other chefs to have three-star New York eateries, have but a handful of restaurants in total. Meanwhile, Wolfgang Puck may now be better known for his frozen pizzas and airport express meals than for the star power of Spago. Though it maintains two Michelin stars, posters on gourmet food boards like Chowhound.com blast the Beverly Hills restaurant for poor service, mediocre food, and "resting on its laurels."

"Consistency is hard," admits Vongerichten, who now spends six hours a day, three weeks a month at his flagship restaurant. His workday begins at 9 a.m. and ends at midnight.