Making a basic white sauce is quite easy and it can be used in many ways. First, melt 2 tablespoons of butter over low heat in a heavy saucepan. Sprinkle two tablespoons of flour over the butter and blend. Keeping the heat on low, stir the mixture constantly for four full minutes. Next, slowly add a cup of milk, once again stirring constantly. Continue cooking and stirring until the sauce thickens. That’s it!