Chowder is a North American cuisine, a hearty soup usually containing fish or shellfish, especially clams. The word chowder is a corruption of the French chaudiere ("cauldron"), and chowder may have originated among Breton fishermen who brought the custom to Newfoundland, whence it spread to Nova Scotia, New Brunswick, and New England. The standard New England-style chowder contains fish or shellfish, salt pork, onions, potatoes, and milk. Manhattan-style chowder replaces the milk with tomatoes. Eighteenth-century chowders were more varied; meat or poultry chowders were made, and wine, spices, herbs, cider, and other flavourings were often added. Pounded common crackers or ship biscuits served as thickening. In the Southern and Midwestern United States, fresh sweet corn (maize) often replaces the clams in chowder. Conch chowder is a specialty of Key West, Florida. [Encyclopedia Britannica]
Any combination of white fish works in this versatile recipe. Experiment!