Preheat oven to 425°. Brown sausage in a large skillet over medium heat, stirring often, 7 minutes or until sausage crumbles and is no longer pink. Add onion and bell pepper, and sauté 3 minutes or until vegetables are tender. Drain. Stir in beans, tomatoes, and salt.
Pour sausage mixture into a lightly greased 13- x 9-inch baking dish. Sprinkle with 1 1/2 cups cheese. Stir together buttermilk and cornmeal mix, and spoon over cheese; sprinkle with remaining 1/2 cup cheese.
Bake at 425° for 25 to 30 minutes or until browned.
Black Bean-and-Chicken Cornbread Casserole: Substitute 1 lb. skinned and boned chicken breasts, chopped, for sausage, and 4 (5-oz.) cans black beans, rinsed and drained, for pinto beans. Stir 1/2 cup chopped fresh cilantro into chicken mixture with beans.