In a skillet over medium heat, cook the ground beef with diced onion and minced garlic until browned. Drain excess fat.

Add black beans, corn, salsa, cumin, chili powder, and salt. Stir to combine and simmer for 5 minutes.

Preheat the oven to 350°F (175°C).

Spread a thin layer of the meat mixture on the bottom of a 9x13 inch baking dish.

Layer 4 tortillas over the meat mixture, followed by half of the remaining meat mixture and half of the shredded cheese.

Repeat the layers, finishing with tortillas and the remaining cheese on top.

Cover the dish with aluminum foil and bake for 20 minutes.

Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and golden.

Let the lasagna cool for a few minutes before slicing. Serve with sour cream, green onions, and cilantro on top.