White Sauce or Bechamel
From The Joy of Cooking, by Irma S. Rombauer and Marion Rombauer Becker, which my mother used regularly, and which was one of my first cookbooks as a young adult.
Makes 1 cup
Melt over low heat: 2 tablespoons butter Add and blend over low heat for 3 to 5 minutes: 1-1/2 to 2 tablespoons flour Stir in slowly: 1 cup milk For better consistency, you may scald the milk beforehand; but be sure—to avoid lumping—that the roux is cool when you add it. Add: 1 small onion studded with 2 or 3 whole cloves ½ small bay leaf Cook and stir the sauce with a wire whisk or wooden spoon until thickened and smooth. Place in a 350 degree oven for 20 minutes to cook slowly. Strain the sauce. Season to taste Add: A grating of nutmeg and serve. For creamed dishes, use about one-half as much as solids.
This basic recipe is the foundation for many variations including cheese sauce and florentine sauce.