In a skillet over medium heat, cook the ground beef until browned. Drain excess fat.

Add chopped onion, bell peppers, and taco seasoning to the skillet. Cook until vegetables are tender.

Stir in black beans and corn, and cook for an additional 5 minutes.

Preheat the oven to 375°F (190°C).

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

Layer 3 tortillas over the salsa, followed by half of the meat mixture, half of the sour cream, and half of the cheese.

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

Cover the baking dish with 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 it cool for 5 minutes before slicing and serving.