Stroganoff Sauce

Heat butter or margarine in a heavy pan; add onion and saute until onion is limp. Stir in flour and cook until blended and bubbly. Slowly stir in broth and cook, stirring until thickened. Mix in sour cream, dill weed, salt and pepper to taste. Do not let sauce boil after sour cream has been added. Reheat over low heat, stirring constantly, just to boiling point. Makes about 3 1/2 to 4 cups.