Preheat oven to 350 degrees Fahrenheit.
In a large skillet, add a small drizzle of oil and brown the beef with onion over medium-high heat. Drain any excess grease from the skillet.
1 pound lean ground beef, 1 brown/yellow onion, olive oil
Stir in taco seasoning with 3 tablespoons of water and simmer for about 7 minutes.
2 tablespoons homemade taco seasoning
Add salsa, black beans, and corn. Give it a good stir and remove it from the heat.
1 can 15-ounce mild salsa, 1 can 15 ounces of black beans, 1 can 15 ounces corn
Lightly grease an 8 or 9-inch casserole dish (I used 8 x 11 inches) with cooking spray or butter. Arrange 2 tortillas at the bottom of the dish and add half of the cooked ground beef mixture and a layer of cheddar cheese (½) on top. Repeat the layers.
2 cups shredded cheddar cheese, 4 taco-size corn tortillas
Bake for 20 minutes until the top is golden brown and casserole bubbly around the edges.
Let the taco bake rest for 5-10 minutes before serving with your favorite taco toppings. Enjoy!