Preheat the oven to 425 degrees F (220 degrees C).
Stir chicken, green enchilada sauce, and 1 cup cheese together in a bowl.
Reserve 2 tablespoons green onions for topping.
Add remaining green onions to chicken mixture, and set aside.
Drizzle oil in the bottom of a deep 9x13-inch baking dish.
Add half the chips to the dish and top evenly with beans and 1 cup cheese.
Pour ¾ cup red enchilada sauce over the top.
Spread chicken mixture evenly over the sauce and top with remaining chips.
Pour remaining red enchilada sauce evenly over the casserole; top with remaining cheese.
Cover with foil.
Bake in the preheated oven for 20 minutes; uncover, and cook until browned and bubbly, about 10 minutes longer.
Serve topped with desired toppings.
