Gefilte fish is an Ashkenazi Jewish dish made from a poached mixture
of ground deboned fish, such as carp, whitefish, or pike, which is
typically eaten as an appetizer
Although the dish historically consisted of a minced-fish forcemeat
stuffed inside the fish skin, as its name implies, since the 19th
century the skin has commonly been omitted and the seasoned fish is
formed into patties similar to quenelles or fish balls. They are
popular on Shabbat and Holidays such as Passover, although they may be
consumed throughout the year.
Originally a stuffed fish,
filled with a mixture of chopped fish, eggs, onions, matzo meal or
crumbs, and spices. Nowadays, it usually refers to poached fish cakes
or a fish loaf, sometimes made with matzo meal.