Bring the water to a boil for the polenta. Whisk in the corn grits and salt, stirring constantly until it thickens. Cover, reduce the flame and simmer 10 minutes.
Preheat the oven to 375°. Evenly spread the polenta on the bottom and sides of a pie plate. Set aside.
Heat the oil in a medium skillet and sauté the onion for 1 to 2 minutes. Add the peppers and sauté another 2 to 3 minutes. Mix in the beans, tomatoes, spaghetti sauce and corn. Simmer for 5 minutes.
Pour the bean and tomato mixture over the polenta and evenly spread it out. Bake 30 to 35 minutes. Remove and allow to cool for 5 minutes before slicing.
Yields 1 pie, 2 slices per person
Per serving - 428 calories, 5 g fat (11% calories from fat), 16 g protein, 80 g carbohydrate, 17 g fiber, 0 mg cholesterol, 140 mg sodium