A cockle is a small, edible bivalve mollusk with a ridged, heart-shaped shell, found in shallow coastal sand and mud flats around the world. Major sources include the coasts of the UK, Spain, and Portugal, as well as parts of East Asia. Cockles have a briny, slightly sweet flavor and a firm, chewy texture, and are typically steamed, boiled, or sautéed with white wine, garlic, and herbs, much like mussels. They're eaten on their own or added to soups, stews, paella, and seafood platters.