Line the bottom of the pan with brown paper. Grease it and the sides of the pan well with butter. Dust the interior with a small amount of cornmeal.
Bring the water to a rapid boil in a saucepan and stir in the grits and salt. Cook over medium heat for 25 minutes, stirring frequently. Beat in the butter when grits are done and remove from heat. In the meantime combine the milk and cornm