Fish stew is a combination of different foods, of which fish is a principal ingredient, which are cooked together. A sauce or gravy is usually produced by the blending of the liquids from the various ingredients; this sauce may be thickened by the use of flour, cream or other thickening agents, like corn starch or tomato sauce. Fish stew may be prepared with the meat of finned fish or with shellfish.
Vegetarian stews and those based on meats, such as pork or beef, are generally permitted to cook for a long time over a low heat, allowing the flavors to blend. The meat of finned fish, and of some shellfish, such as oysters, is very delicate, however, and will not stand up to long periods of cooking, especially in a liquid. For this reason, fish should be added to fish stew only near the end of cooking; also, once the fish is in the stew, rapid boiling is generally avoided to prevent its disintegration.
Different regions have their own styles of fish stew, from the cream-based chowders of New England to the southeast Asian fish stews based on coconut milk. Various vegetables — generally whatever is in season — are usually cut into bite-sized pieces and allowed to simmer in the liquid, which can be fish broth, clam juice, chicken broth, or whatever else the recipe or the cook’s taste may call for. Spices added to the stew can be strong because fish absorb their flavors well, and many cooks supplement the liquid with wine.
Perhaps the most famous fish stew is bouillabaisse, which is traditionally said to have originated in the French port town of Marseilles and relies on a variety of freshly caught fish and shellfish from the Mediterranean, and Provençale spices, as well as fennel, orange peel and saffron, for its unique flavor. Bouillabaisse differs from most other fish stews in that it calls for the introduction of the fish ingredients into a rapidly boiling broth and continuing a rapid boil for 15 – 20 minutes. Another very well-known fish stew is clam chowder, which combines shelled clams, potatoes and onions. New England clam chowder uses cream and clam juice as its main liquid, while Manhattan clam chowder is tomato-based.
To prepare fish stew, the cook should select the very freshest white-fleshed fish, such as halibut, hake, pollock, cod, red snapper, sea perch, or pompano; shellfish should also be as fresh as possible. Interesting variations can be developed from stronger-tasting fish like bluefish and mackerel. Canned vegetables should be avoided; if fresh vegetables are unavailable, the cook should use frozen. As with any recipe, when making fish stew, cooks should have all ingredients prepared and measured before starting.