Preheat oven to 375 degrees F. Spray a 10x15 inch baking sheet with nonstick spray or line with foil.
Spread half the tortilla chips evenly over prepared baking sheet. Sprinkle 1 cup of cheese over the chips.
Place black beans in a medium microwave safe bowl and heat until warmed (around 45 seconds). Spread half the beans and also half of the shredded Mexican chicken evenly over the tops of chips and cheese.
Repeat layers one more time ending with the cheese.
Bake for 10 minutes or until cheese is melted. Remove from oven and top with tomato and green onion. Serve with desired toppings and enjoy!