Gratin Sauce (for Fish).—Peel and chop finely one eschalot and four or five good-sized, well-washed mushrooms (fresh, if possible), and put these in a stewpan, with one table- spoonful of finely chopped parsley, two glasses of sherry, and half an ounce of glaze; reduce these a quarter part, then add about half a pint of good thick brown sauce, a teaspoon- ful of essence of anchovy, and cook all together for about five minutes, then take up and pour over the fish.