Clean the fish and sut off the head, if preferred; cut out the backbone to within two inches of the tail, and stuff the fish with the following mixture : Soak stale bread in water; fry in butter a large onion, and chop fine ; add the bread, squeezed dry, two ounces of butter, and salt, pepper, and a little parsley or sage; heat through, take off the fire, and add the yolks of two well-beaten eggs. Sew the fish, when filled, with fine twine, and wrap with several coils of white tape. Rub it over slightly with butter, cover the bottom of a baking pan with hot water, and place the fish in it, back upward. Serve with the following dressing: Reduce the yolks of two hard-boiled eggs to a smooth paste with two tablespoonfuls good salad oil; stir in half a teaspoonful English mustard, and add pepper and vinegar to taste.