Preparation

• Melt the butter in a heavy-bottomed saucepan. Stir in the flour and cook, stirring constantly, until the paste cooks and bubbles a bit, but don't let it brown - about 2 minutes.
  Add the hot milk, continuing to stir as the sauce thickens. Bring it to a boil. Add salt and pepper to taste and nutmeg; lower the heat, and cook, stirring for 2 to 3 minutes more.
  Remove from the heat. To cool this sauce for later use, cover it with wax paper to prevent a skin from forming.
  Cheese Sauce. Stir in 1/2 cup grated Cheddar cheese during the last 2 minutes of cooking, along with a pinch of cayenne pepper.