Follow the proportions as given for "Sauce Bordelaise," the Marrow Sauce being only a variety of Bordelaise. Finish it with six ounces per quart of beef marrow, cut into cubes, poached and well drained, and one teaspoonful of chopped parsley, blanched. If the sauce is to accompany vegetables finish it, away from the fire, with three ounces of butter, and then add the cubes of marrow and the parsley.