1Heat oven to 400°F. In 12-inch cast-iron skillet, heat oil over medium-high heat. Cook onion and bell pepper in oil 4 minutes or until tender. Add sausage; cook 2 minutes. Stir in sweet potatoes, broth, salt and pepper. Remove from heat. Sprinkle with cheese.
2In medium bowl, stir cornbread mix, buttermilk, butter and egg just until moistened. Spread over cheese and sausage mixture to within 2 inches of edges.
3Bake 16 to 20 minutes or until top is golden brown.