White sauce, also known as béchamel, is a classic French sauce made from a simple mixture of butter, flour, and milk. It serves as a base for many other sauces and dishes, providing a creamy texture and mild flavor. White sauce is often used in recipes like lasagna, macaroni and cheese, and various casseroles. To prepare white sauce, equal parts of butter and flour are cooked together to form a roux, which is then gradually whisked with milk until it thickens. Seasonings like salt, pepper, and nutmeg can be added for extra flavor. This versatile sauce is a staple in many cuisines around the world.