Place a large skillet over medium heat. Add ground beef and cook until browned and no longer pink. Do not drain.
Add taco seasoning to beef and stir until combined.
Add corn, tomatoes, black beans, and 1/4 cup salsa to the ground beef and stir to combine. Set aside.
Place 2 tablespoons salsa in the bottom of a 9-inch x 13-inch pan and spread to cover the bottom. Layer with 5 tortillas (4 whole and one cut in half to fill in the gap.)
Add 1/2 of the beef mixture over the tortillas and then sprinkle with 1 cup cheese. Repeat layers - tortillas, remaining beef mixture, and 1 cup cheese.
Top lasagna with 5 tortillas just like the previous layers. Spread remaining 2 tablespoons salsa over the tortillas. Sprinkle on remaining 1/2 cup cheese.
Bake for 30 minutes, or until cheese is melted and lasagna is bubbling.
Remove from oven and allow to rest for 10 minutes before serving. Cut into 6-8 slices, plate lasagna, and top with sour cream and green onion for garnish if desired.
Notes
You can use whatever salsa you like for this recipe. It's a great way to add extra heat or keep things mild depending on your taste preference.