Knopf, the 87-year-old widow of motion-picture producer Edwin H. Knopf (whose brother was publisher Alfred A. Knopf), has entertained many a luminary in her day. Her cookbook sounds as though she's giving instructions to her newest cook-servant: FIRST, do this. . . Her dictatorial exhortations are interspersed with stories and anecdotes, intended to be charming but more often pointless and off-putting. She offers a recipe for ""Banana and Bacon Bits,"" for example, because it was being served by the pool at the Biltmore in Phoenix the day she and her husband bumped into ""old friends"" Nancy and Ronald Reagan. Does Nancy like banana and bacon bits with her before-dinner drinks? We'll never know because Knopf doesn't say. The recipes, meant to be memorable or nostalgic, are more often anachronistic. Would a modern hostess dream of making a Jello salad for dinner-party guests? Just in case, Knopf gives three such recipes. Would even a beginner in the kitchen want to add Worchestershire sauce to practically every savory dish? Knopf does. Would today's health-conscious cooks and diners want to use butter, flour, and heavy cream as lavishly as Knopf suggests? Doubtful. Knopf obviously loves to eat, travel, entertain, and give cooking instructions. Unfortunately, these qualities do not comprise the complete recipe for writing a good cookbook.