The thick, creamy French soup made from pureed shellfish is called bisque.
Classical bisque is a smooth soup built from crustaceans such as lobster, crab, shrimp, crayfish, or langoustine. The shells are commonly sautéed and simmered with aromatics and wine to extract deep flavor; the broth is then strained and enriched with cream. Rice may also be used as a thickener.
The word has a more varied history than many diners realize. Earlier French bisques could be made with game birds, including pigeon, before seafood became the defining association. The name may derive from the Bay of Biscay, although another theory connects it with bis cuites, meaning “cooked twice.”
Bisque is often confused with chowder. Both can contain seafood, but chowder is generally chunky, while bisque is characteristically smooth. Modern menus also use “bisque” for creamy puréed soups made from vegetables such as tomato, squash, or mushroom, even when no shellfish is present.