Mornay is a creamy cheese sauce that originates from French cuisine. It is typically made by adding cheese, usually Gruyère or Emmental, to a basic béchamel sauce, which consists of butter, flour, and milk. This sauce is often used in various dishes, such as macaroni and cheese or as a topping for vegetables and seafood. The sauce is named after the 16th-century French nobleman Philippe de Mornay, who is credited with popularizing it. Mornay sauce is versatile and can be enhanced with additional ingredients like nutmeg or mustard to complement different recipes.