Preparing a Passover seder for twenty? Or a Purim feast for six? Or making a kosher meal to impress the in-laws? Whether it's grand-scale celebrating or a cozy simple at-home meal, cooking traditional Jewish fare is one of life's great joys. Yet preparing all those favorites you grew up with--like challah, hamantaschen, a roast leg of lamb drizzled in herbs--delicious enough to please a roomful of hungry guests as well as fulfill holiday expectations...