Bring 2 2/3 cups water to a boil; gradually whisk in grits, and cook, stirring often, 5 minutes or until thickened. Remove from heat. Add margarine and next 4 ingredients; stir until blended. Spoon into a lightly greased 8-inch baking dish.
Bake at 350º for 40 minutes, or until lightly browned.
Note: Casserole may be prepared and chilled up to 24 hours before baking. Let stand at room temperature 30 minutes; bake as directed