Creating Walking Taco Casserole is simple and straightforward if you follow these easy steps:

1. Preheat Oven: Start by preheating your oven to 350°F (175°C).
2. Brown the Meat: In a large skillet, cook the ground beef over medium-high heat until browned. Drain excess fat if needed.
3. Season the Meat: Add the taco seasoning and mix well, cooking for an additional 2-3 minutes to let the flavors meld.
4. Combine Ingredients: Stir in the diced tomatoes, corn, and black beans (if using). Mix everything until well combined and heated through.
5. Prepare the Casserole Dish: In a greased 9×13-inch casserole dish, layer half of the crushed tortilla chips at the bottom.
6. Add Meat Mixture: Spoon half of the meat and tomato mixture over the tortilla chips, spreading it evenly.
7. Add Cheese: Sprinkle 1 cup of shredded cheese over the meat layer.
8. Repeat Layers: Add the remaining tortilla chips, followed by the remaining meat mixture, and top with the remaining cheese.
9. Bake the Casserole: Place the casserole dish in the preheated oven and bake for 20-25 minutes, or until the cheese is melted and bubbly.
10. Add Toppings: Once baked, remove from the oven and let it cool slightly. Top with dollops of sour cream, chopped green onions, and fresh cilantro, if desired.

This step-by-step guide will ensure that your Walking Taco Casserole turns out perfectly every time!