Fish stock, also called fish fumet, is normally prepared with bones and trimmings of lean flatfish such as sole and flounder. Oily varieties of fish, such as salmon and mackerel, should be avoided except when preparing red wine sauces. In areas where fresh fish is abundant (an increasingly rare occurrence), fish stock can be made with fresh baby whole fish rather than bones. Whether fish or fish bones are being used, it is essential they be impeccably fresh and that the fish stock be prepar