 Although many, if not most, Jews in Israel do not keep kosher, the tradition of "kashrut" strongly influences the availability of certain foods and their preparation in homes, public institutions and many restaurants, including the separation of milk and meat and avoiding the use of non-kosher foods, especially pork and shellfish.During Passover, bread and other leavened foods are prohibited to observant Jews and matza and leaven-free foods are substituted.Israel does not have a universally recognized national dish; in previous years this was considered to be falafel, deep fried balls of seasoned, ground chickpeas.