Wet commeal with 2 tablespoons cold milk, and let stand while 2 cups milk scald.
Add commeal, sugar, and salt to hot milk and cook, covered, over hot water for 20-30 minutes or until slightly thickened.
Mix beaten egg with 1/4 cup cold milk, and pour slowly into commeal mixture, stirring.
Remove from heat and serve.
Top each bowl with dot of butter.