Preheat the oven to 350°F (175°C). Lightly spray a 10–12 inch oven-proof skillet or baking dish with cooking spray.
Layer five 6-inch tortillas in the bottom of the skillet or dish, overlapping to cover the base.
Top the tortillas with half of the shredded chicken, half of the salsa verde, half of the black beans, half of the corn, and half of the shredded cheese, spreading evenly.
Repeat the layers with the remaining tortillas, chicken, salsa verde, beans, corn, and cheese, ensuring the top layer of tortillas is well covered with salsa so they stay moist.
Bake uncovered in the preheated oven for 20–30 minutes, until the cheese is melted and bubbly and the filling is heated through.
Remove from the oven, sprinkle with sliced green onions, slice into triangles, and serve with desired toppings such as sour cream.