Step 1: Preheat your oven to 350°F (175°C) and prepare your baking dish by greasing it.
Step 2: In a large skillet, sauté chopped onion and diced red bell pepper until soft, about 5 minutes.
Step 3: Add ground beef to the skillet and cook until browned, breaking it apart as it cooks.
Step 4: Stir in taco seasoning, Rotel tomatoes, black beans, and corn. Simmer for 5 minutes.
Step 5: In a mixing bowl, mix cream cheese with 1 cup of salsa until smooth.
Step 6: Assemble the lasagna in the baking dish: layer beef mixture, tortillas, cream cheese mixture, and shredded cheese.
Step 7: Cover with foil and bake for 25 minutes; remove foil and bake for an additional 10-15 minutes.
Step 8: Let cool for a few minutes, then slice and serve with toppings like sour cream or guacamole.