Marshall, a Parisian transplant, is an expert cooking instructor. Her Greenwich Village school, A La Bonne Cocotte (At the Good Cooking Pot), has been judged "a no-nonsense place that is the best in town" by the New York Times. Students—Woody Allen is an alumnus—usually wait a year to be accepted for the $65-a-lesson classes. Marshall's specialty is down-to-earth French cooking, but her meals are not down-scale. "They can be elegant," she says. "They can be well presented." She been privately slaving over her tell-all book, Cooking With Lydie Marshall (Knopf). The book is divided into 22 it takes neophytes from simple basics like tossed green salad vinaigrette to dishes like poached fish mousse. (excerpted from People Magazine, 1982)