Cocktail sauce is the bright-red, cold, sharp seafood sauce built to be dipped into — the near-universal accompaniment to chilled shrimp, oysters and crab in the English-speaking world. At its simplest it is ketchup or a sweeter tomato "chili sauce" fired up with grated horseradish and a squeeze of lemon, seasoned with Worcestershire sauce and a shake of hot sauce, giving a sweet-tangy tomato base with a sinus-clearing horseradish kick. It is served raw and cold, in a small dish alongside the seafood rather than cooked into it.