01 -
Heat your oven to 350°F. Spray a 9x13 inch baking dish with cooking spray and set it aside.
02 -
Brown the ground beef and diced onion in a large skillet over medium heat. Cook until the meat is no longer pink and the onions are soft.
03 -
Stir in the minced garlic and cook for another minute until fragrant. Add taco seasoning and water, stirring until everything is well mixed.
04 -
Add the diced tomatoes with their juices, green chiles, and drained black beans. Stir everything together and let it heat through.
05 -
Arrange 6 corn tortillas in the bottom of your prepared baking dish, overlapping them slightly to cover the entire bottom.
06 -
Spread one-third of the meat mixture over the tortillas, then sprinkle 2 cups of cheese on top. Repeat this process two more times for three complete layers.
07 -
Cover tightly with aluminum foil and bake for 30-40 minutes until the casserole is bubbling and the cheese is completely melted.
08 -
Let the lasagna sit for 10 minutes before cutting - this helps it hold together. Top with diced tomatoes and green onions, and serve with sour cream.