Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking dish with cooking spray or butter.
2. Brown the Beef:
In a large skillet over medium heat, cook the ground beef and diced onion until the beef is browned and the onion is translucent, about 5-7 minutes. Drain excess fat if needed.
3. Season and Combine:
Add the taco seasoning to the cooked beef and onions, stirring well to coat evenly. Then, add the drained black beans, corn, and diced tomatoes with green chilies. Mix everything together and let it simmer for another 3-5 minutes.
4. Layer the Casserole:
Spread a layer of half the tortilla chips at the bottom of the prepared baking dish. Spoon half of the beef mixture over the chips. Sprinkle a cup of shredded cheddar cheese on top.
5. Repeat Layers:
Add another layer of the remaining tortilla chips, followed by the rest of the beef mixture. Finish with the remaining cup of shredded cheddar cheese, ensuring even coverage.