Hanukkah, the celebration of the miracle of light, is actually a minor holiday in the Jewish calendar. But it’s a focal point this time of year because it’s close to Christmas and involves eating lots of fried foods with abandon. American Jews represent a diaspora that began 2000 years ago, a long enough time to become culinarily acculturated all over the world. Leah Koenig’s epic “ The Jewish Cookbook ” contains a variety of dishes that span the world.