Preheat your oven to 350°F (175°C). Generously grease a 9×13-inch baking dish with cooking spray or olive oil.

In a large skillet over medium heat, add 1 pound of ground beef along with 1 diced onion. Cook for 5-7 minutes, stirring frequently until the beef is browned and onion is translucent.

Stir in 2 cloves of minced garlic and sauté for 1-2 minutes until fragrant. Sprinkle in 2 packets of taco seasoning, followed by 0.5 cup of water. Allow to simmer for 1 minute.

Add 14.5 ounces of fire-roasted diced tomatoes, 4 ounces of green chiles, and 1 drained can of black beans to the skillet. Stir and heat through for 3-5 minutes.

Layer 6 corn tortillas in the bottom of the greased baking dish, slightly overlapping each one.

Spread one-third of the meat mixture over the tortillas, then top with 2 cups of shredded cheese. Repeat this process two more times.

For the final layer, add the last tortillas and sprinkle remaining cheese on top.

Cover the dish with foil and bake for 30-40 minutes until bubbly and heated through.

Let the lasagna rest for about 10 minutes before serving. Garnish with chopped tomatoes, green onions, and sour cream.