For a classic white sauce served with seafood, also called Béchamel sauce, gather 1 cup milk, 2 crushed garlic cloves, 2 tablespoons of flour and 2 bay leaves, Also prepare a pinch of salt and some white pepper to taste. Simmer gently over low heat until sauce thickens.
Place the milk in a small sauce pan with one bay leaf, Heat it through, ensuring that the heat remains low so that the milk does not scorch. In a thick-bottomed sauce pan, melt the butter, waiting until the foaminess all but disappears. Add the flour and cook the contents for about three minutes, stirring constantly with a wooden spoon to avoid lumps. Do not allow this, the sauce's roux, to brown.
Add some of the warmed milk to the roux, stirring vigorously with a whisk. Again, keep the heat on low to avoid scalding and clumping. Keep adding small amounts of the milk and stirring until the sauce has enough thickness to fully coat the back of the wooden spoon, At this point, add the salt, white pepper, the second bay leaf and the crushed garlic. Taste for seasoning, and adjust if necessary. If allowing the sauce to cool, place plastic wrap tightly on top to avoid a skin forming on the surface. This sauce and its variations, such as Mornay or Nantua, are especially delicious with whitefish, shellfish, seafood stews, pies and casseroles.