Preheat the oven to 350°F (175°C).
Shred the cooked chicken into bite-sized pieces.
Measure and prepare all ingredients.
Cut corn tortillas into 1-inch wide strips.
Grease a 9x13-inch baking dish and layer half of the tortilla strips on the bottom.
In a large bowl, mix shredded chicken, salsa verde, sour cream, garlic powder, cumin, chili powder, corn, black beans, salt, and pepper. Spread half of this mixture over the tortilla layer.
Sprinkle half of the shredded cheese on top of the chicken mixture.
Repeat the layering process with remaining tortilla strips, chicken mixture, and cheese.
Cover with aluminum foil and bake for 25 minutes.
Remove foil and bake for an additional 10-15 minutes until cheese is bubbly and golden brown.
Let cool for 5 minutes before serving.