Fast food has to be one of America's least-appetizing exports. The industry offers bland products, miserable employees, and an approach to strategy that celebrates conformity. London-based Pret A Manger, a fast-growing force in the quick-serve business, has concocted a recipe for reinvention -- and now it's exporting its ideas to the Home of the Whopper.

Pret A Manger (the name is faux French for "ready to eat") operates 118 shops in the United Kingdom, along with 5 in New York and one in Hong Kong. Entering one of its restaurants is like stepping inside a giant, bright, stainless-steel lunch box. On the left is a wall of open, clean, refrigerated shelves stocked with sandwiches made fresh that day, in that shop, primarily from ingredients delivered earlier that morning. (Customers can also choose from other freshly made items, such as salads, yogurt parfaits, blended juices, and sushi.) At the back of the cozy space is a counter where customers can order espresso and pay for their meals. To the right is a small seating area filled with stools and cafe tables -- although, on average, customers spend just 90 seconds from the time they get in line to the time they leave the shop.

Founded in 1986, Pret aims to be the fast-food chain that elevates expectations about what fast food can be -- and that writes the book on how to grow a fast-food empire while holding on to its integrity. "Growth is sexy, but it's also dangerous," says chairman and CEO Andrew Rolfe. "We ask, How do we grow this business in such a way that we're still proud of it?"

Pret's most powerful insight: You can organize a mass-market business around innovation rather than standardization. Last year, the company introduced 111 new items to its menu (and retired almost as many). It is constantly tweaking the menu choices. Pret's brownie recipe has been revised more than 30 times in pursuit of perfection. Rolfe holds his head in his hands, Hamlet-like, when he considers the possibility of introducing hot croissants to the menu. Will the fillings dry out too easily? There's only one way to find out. "We don't believe in focus groups, research, or advertising," says Rolfe. "We have a very simple principle: If it doesn't take, we stop selling it."

Pret doesn't mass-produce employees either. Frontline workers aren't pigeonholed into performing repetitious tasks all day, they aren't given scripts, and they're treated to weekly Pret-organized pub nights. Many long-serving store managers have equity in the company, and few work nights or weekends -- which is a rarity in the restaurant business.

Rolfe, who was VP of European operations for PepsiCo Restaurants International before he joined Pret, understands that his company poses a challenge to conventional wisdom in his business. And he is hungry to test his strategies in the United States. "Since World War II, America has given the world Burger King, KFC, McDonald's, and Pizza Hut," Rolfe says. "Nobody has ever gone to America, the home of fast food, with a concept that turned out to be a successful national chain. We think we can do that."

But changing the game doesn't mean working alone. In early 2001, Pret brought on a powerful partner to help with its conquest of North America and the world: the McDonald's Corp., which bought a 33% stake. Rolfe says that the fast-food behemoth has already been a big help in cutting real-estate deals in Hong Kong, for example. Rank-and-file employees worried that McDonald's might somehow corrupt Pret's values or its dedication to healthy, carefully made food. Rolfe is less concerned. "We have a strong focus on food and a strong entrepreneurial spirit," he explains.