Bechamel sauce is made from very simple ingredients: butter, milk, flour, and salt. It can also incorporate different herbs or spices, such as nutmeg, bay leaf or paprika. Considered one of the classic French mother sauces, Bechamel is often used as a base sauce for more complex preparations.
One of the most important components of a proper Bechamel sauce is the roux, a reduction of flour and butter that thickens the sauce and adds texture. Butter is melted over low to medium heat, then the flour is whisked in and the temperature raised to medium while the cook continues to stir the roux. Over the course of the next six to seven minutes, the mixture starts to turn a golden or sandy color.
In a separate pan, the milk is heated, being constantly stirred to avoid scalding. Some recipes split the quantity of milk in half, substituting chicken stock for the omitted dairy. The just-boiling liquid is then transferred into the pan containing the roux and whisked vigorously until smooth. The sauce is then brought back to a boil, and cooked for an additional 10 minutes, being stirred constantly. Once finished, the sauce is removed from the heat, and seasoning is adjusted if necessary.