Preheat oven to 375 degrees.
In a bowl, mix together chicken, corn, diced tomatoes, taco seasoning, sour cream, and 1 cup of cheese.
Transfer into a 10-inch cast iron pan or a casserole dish that is approximately the same size.
Mix together cornbread mix, whatever liquid your cornbread packet calls for, egg, and remaining cheese. Pour on top of chicken mixture.
Place in oven and bake for about 25 minutes. Let cool slightly before cutting into wedges.
