Peel and cut up two good-sized onions, put them in a stewpan with an ounce of butter till they are a nice yellow color, then add eight tablespoonfuls of demi-glaze, and two of water or broth ; skim, boil quick ; when a proper thickness, add a good tablespoonful of French mustard; season it rather high ; if no French mustard, use English, but it completely changes the flavor, though still very palatable.