Preheat oven to 375*
Heat oil in a 12 inch cast iron skillet, add onion, bell pepper, and garlic. Saute until tender.
Add ground turkey, chili powder, cumin, and cayenne pepper. Cook, breaking up turkey, until turkey is no longer pink and begins to brown.
Add drained bean, tomatoes, and salsa.
Simmer for 15 minutes.
Stir in corn.
Top with sliced polenta.
Sprinkle cheese over top.
Bake, uncovered, for approx 20 minutes, or until hot, bubbly, and beginning to brown.
Before serving, top with diced tomatoes and chopped cilantro.
Serve and add additional toppings as desired (avocado and sour cream).