in a large pan sauté the ground meat, breaking it up with a spatula. drain excess liquid and transfer to a large bowl.
to the bowl, add the diced tomatoes, taco seasoning, bell pepper, corn, and optional black beans. mix it up until well combined.
start by covering the base with tortillas (arrange them so there are no holes). next, add ⅓ of the mixture from the bowl. sprinkle with ⅓ of cheese.
cover casserole and bake for 20 minutes. uncover and bake for another 10 minutes.