In a large Cast Iron skillet, over medium heat, add the oil and onion, saute until softened about 2-3 minutes, add the garlic and fry until fragrant. Stir in the bell peppers and saute about 2 minutes until slightly softened.
Add the chili powder and cumin, and stir. Add the salsa, diced tomatoes,beans, lentils and corn and bring to a simmer. Simmer for about 5 minutes while you prepare the cornbread batter.
In a bowl mix together the cornmeal, flour, sugar, baking powder and salt. Add the oil and milk and mix. It should be the consistency of pancake batter.
Sprinkle shredded cheese evenly over the corn/black bean mixture, then pour the cornbread mixture over top to cover.
Place skillet in the oven and bake for 25-30 minutes or until the top is golden brown.
Notes
If you don't want to make the cornbread mixture from scratch, you can easily use any cornbread mix. Follow the directions on the package, but increase the milk to 1 cup so as to make a thinner batter that will pour easily.If you want to make this a complete meal in a skillet, you can add ground beef or turkey, spicy Italian Sausage, or Chorizo. It's very flexible.