The classic French white sauce made from milk and a butter-and-flour roux is béchamel.
Béchamel begins with a roux: butter and flour cooked together so the flour thickens liquid without forming lumps. Milk is then gradually whisked in, producing a smooth white sauce often seasoned with salt, pepper, and nutmeg. It is one of the five “mother sauces” of classical French cuisine.
A related early recipe appeared in François Pierre de La Varenne’s 1651 cookbook Le cuisinier françois. The sauce’s name is commonly connected with Louis de Béchameil, a 17th-century financier and court official associated with Louis XIV, although the exact credit for its creation is uncertain. Claims that it was imported directly from Catherine de’ Medici’s Tuscan kitchens are generally treated as a later culinary legend.
Béchamel is frequently confused with velouté, another French mother sauce. Velouté uses a light stock rather than milk. Hollandaise is an emulsified butter-and-egg-yolk sauce, while espagnole is a brown sauce based on stock. Béchamel also serves as the foundation for Mornay sauce, which adds cheese, and appears in dishes such as lasagne and gratins.