In 12 inch iron skillet, melt generous amount of butter. Put tomato halves (cut-side up) to fill pan and cook over high heat. Sprinkle flour, salt to taste and a bit of sugar over each. Cook 5 minutes. Turn over. Some bottoms will be burned slightly which enhances the flavor. Cook until soft. Remove from stove. Stir in 4 tablespoons of flour and add 1 1/2 cups milk. Heat and stir to a thick gravy. Simmer over low heat until served. Delicious with scrambled eggs, fried chicken, or fish.