1. Preheat your oven to 350°F (175°C).
2. In a large skillet over medium heat, cook the ground beef until browned, breaking it up with a spoon as it cooks, about 5-7 minutes.
3. Drain excess fat and stir in the taco seasoning. Add a splash of water if necessary to distribute the seasoning evenly.
4. Add the black beans, corn, and diced tomatoes with green chilies to the skillet, mixing everything together well.
5. In a 9×13 inch baking dish, layer half of the corn chips, then spread the beef mixture evenly over the chips.
6. Sprinkle half of the shredded cheddar cheese over the beef mixture.
7. Add the remaining corn chips on top, followed by the remaining cheese.
8. Bake in the preheated oven for about 15-20 minutes, or until the cheese is melted and bubbly.
9. Remove from oven and let it cool slightly before topping with dollops of sour cream, green onions, and cilantro.

One tip I’ve learned from trial and error: let the casserole cool for a few minutes before serving to let everything set a bit. This makes serving easier and helps the flavors meld beautifully.