Preheat oven to 400. Spray casserole dish with cooking spray. In skillet saute onion in a pat of butter. Add beef and brown. Stir in taco or chili seasoning. ( You can substitute leftover ground beef for this step). Add beans, tomatoes, red pepper flakes, and salt and pepper combine and pour into casserole dish.
Next, combine cornmeal, flour, baking powder, salt and pepper in mixing bowl. In a seperate bowl, mix egg and sour cream or yogurt until smooth. Stir in butter, corn, and 1/2 cup cheese. Add the wet mix to the dry ingredients and stir until just combined.
Spoon the batter around the edges of the casserole. Leave the middle open.
Sprinkle remaining cheese all over.
Bake for 20-30 minutes until cornbread is lightly browned and beans are nice and bubbly.