1 (12 fluid ounce) can enchilada sauce
- Preheat an oven to 375 degrees F (190 degrees C). Prepare a 9×13-inch baking dish with cooking spray.
- Cook the ground beef in a skillet over medium heat until completely browned, 5 to 7 minutes. Add the onion, garlic, taco seasoning mix, frozen Mexican-style corn, and black beans to the ground beef; cook and stir another 10 minutes. Set aside to cool slightly.
- Combine the ground beef mixture in a large bowl with about 3/4 of the Mexican cheese blend and the tater tots; stir to combine.
- Pour about 1/3 of the enchilada sauce into the bottom of the prepared baking dish. Add the tater tot mixture to the baking dish; lightly pat the mixture down into a solid, even layer. Pour the remaining enchilada sauce over the tater tot layer.
- Bake in the preheated oven for 40 minutes. Sprinkle the remaining Mexican cheese over the casserole and return to oven until the cheese is melted and bubbly, about 5 minutes more.