Put four ounces of fresh butter into a stewpan on the fire, and keep stirring it until it becomes browned by frying; then add a small wineglassful of tarragon vinegar, ditto of Harvey, a tablespoonful of chopped capers, a little anchovy, and either a gill of brown sauce or gravy; boil this together for five minutes, and serve over boiled skate or grilled mackerel.