Preheat the oven to 350 degrees Fahrenheit. Spray a 9x13 casserole dish with non-stick cooking spray and set aside.
Cook ground beef and onion in a large skillet over medium heat until the meat is browned and the onions softens.
Add minced garlic to the skillet and saute for 1-2 minutes longer.
Add taco seasoning and water and stir over medium heat until well combined.
Stir the tomatoes (juices included), green chiles, and black beans into the meat mixture and heat through.
Line the prepared baking dish with 6 corn tortillas, overlapping slightly to cover the bottom of the casserole dish.
Spread 1⁄3 of the meat mixture over the tortillas. Sprinkle 2 cups of the cheese over the meat mixture.
Continue layering corn tortillas, meat mixture, and cheese to form three layers total.
Cover with aluminum foil and bake for 30-40 minutes until casserole is bubbly and the cheese is fully melted.
Garnish with diced tomatoes and green onion. Let the casserole sit for 10 minutes for easy slicing and serving.
Serve with sour cream.
Video
Notes
You can use salsa instead of the fire roasted tomatoes - I would recommend 1 1⁄2 cups of salsa. The juices in the tomatoes (or the salsa) provides the necessary moisture for the dish. Since we’re layering with corn tortillas, the filling needs that moisture.
If desired, you can substitute ground turkey for the ground beef. You can even use shredded beef, chicken, or pork if that your tastes better.
Frozen or canned corn can be added to the meat mixture in the skillet if desired.