In a large skillet over medium heat, brown the ground beef or turkey, breaking it apart with a spatula until fully cooked. Drain excess fat.
Stir in the black beans, corn, diced tomatoes with green chilies, taco seasoning, and salsa. Mix well and let it simmer for about 5 minutes to allow flavors to meld.
In a greased 9x13 inch baking dish, layer half of the crushed tortilla chips on the bottom.
Spread half of the meat mixture over the chips, followed by half of the shredded cheddar cheese.
Repeat the layering process: another layer of chips, meat mixture, and top with the remaining cheddar cheese.
Cover the dish with aluminum foil and bake in the preheated oven for 25 minutes.
Remove the foil and bake for an additional 10-15 minutes, until the cheese is bubbly and golden.
Allow the casserole to cool slightly for about 5 minutes before serving.
Serve with dollops of sour cream on top and garnish with chopped green onions and fresh cilantro if desired.
Notes
Feel free to customize with your favorite toppings.