Making Walking Taco Casserole is straightforward when you follow these step-by-step instructions:

1. Preheat the Oven: Start by preheating your oven to 350°F (175°C).
2. Cook the Beef: In a large skillet over medium heat, cook the ground beef until it’s no longer pink. Drain the excess fat.
3. Add Seasoning: Stir in the taco seasoning according to package instructions, adding water if needed and following the suggested cooking time.
4. Combine Ingredients: Mix in the black beans, corn, and salsa. Stir well until everything is heated through.
5. Layer the Dish: In a 9×13-inch baking dish, layer half of the crushed tortilla chips.
6. Add Meat Mixture: Spoon half of the beef mixture over the tortilla chips, followed by one cup of shredded cheddar cheese.
7. Repeat Layers: Create another layer with the remaining chips, the rest of the beef mixture, and top with the remaining cheddar cheese.
8. Bake: Place the baking dish in the preheated oven. Bake for 30-35 minutes or until the cheese is melted and bubbly.
9. Cool: Remove from the oven and let it cool for 10-15 minutes.
10. Add Toppings: Before serving, dollop sour cream on top. Then add diced tomatoes, olives, green onions, and avocado, if using.

These simple steps will guide you in creating this delicious and hearty casserole that can be made effortlessly.