Take off all flesh from the fish bones. Mash up a few potatoes. Season to taste. Grease paper bag. Place mashed potatoes at the bottom, flat. Put one teaspoonful of flour on the top of the fish, three tablespoonfuls of milk, salt and pepper, a little chopped parsley (if desired), anchovy or other sauce. Mix together. Place the mixture on top of the potato and put in the bag. Seal up, and place on the grid. Allow fifteen minutes in a hot oven (350 Fahr.).