In the bad old days, when rich sauces ruled and vegetables were but a garnish, chefs were not experts on low-fat food. Even the best of them were likely to fill requests for a health-conscious meal with a plain fish fillet, a lemon wedge and an undressed salad. But times have changed. Over the past 15 years, in response to customer demands, many top chefs have become masters at cooking with less butter and oil. We found three who are known for creative, delicious low-fat fare and asked them to design menus for home cooks. Hubert Keller, of Fleur de Lys in San Francisco, makes stars of once humble vegetables, roasting them to concentrate flavor and serving them with substantial starches and grains. Allen Susser, of Chef Allen's in Miami, relies on fruit-based sauces and salsas that don't need fat-laden additives for balance. And Vincent Guerithault, of Vincent Guerithault on Camelback in Phoenix, uses intensely flavored condiments, like pesto and chipotle chutney, to dress up his food. These low-fat menus are worth going out for--but they're also easy to make at home.