Ackart isn't trying to convert anyone to vegetarianism as a creed--he enjoys meat and poultry himself--but rather to point up the many taste possibilities of meatless meals. The soufflÃ‰ is his forte--he serves it as first course, entrÃ‰e, and dessert--and he persuades asparagus, lemon, creamed corn, and canned plums to transcend themselves. Recipes are printed in such a way as to clearly separate do-ahead jobs from last minute preparations and facilitate leisurely entertaining. Unfortunately, Ackart occasionally presses too hard to be distinctive or festive and comes up with such problematic dishes as mushrooms in orange sauce or sweet potato soup. The menus are arranged seasonally but there's no reason at all not to confuse the seasons as the palate dictates.