This dish, which is the Italian version of French bouillabaisse, can be prepared any time, depending on the availability of fish. Generally, it can be served as a meal in itself with a mixed green salad, and some bread. If you intend to serve other dishes as well, these quantities will serve more than six. The separate preparation of all the fish may seem daunting, but the end result is a worthwhile, beautiful bowl of mixed seafood.