The main ingredient in a béchamel sauce is milk, combined with a roux made from equal parts of flour and butter. Béchamel is one of the basic mother sauces in French cuisine and serves as a base for many derivative sauces, such as cheese sauce (Mornay) and mustard sauce. To prepare béchamel, the roux is cooked to a white color, then slowly whisked with warm milk to create a smooth, creamy consistency. Seasoning, typically with salt, white pepper, and sometimes nutmeg, enhances the flavor. This versatile sauce is widely used in lasagna, macaroni and cheese, and various gratin dishes.