In a large mixing bowl, combine the shredded chicken, sliced bell pepper, onion, corn, black beans, salsa, chili powder, cumin, and half of the shredded cheese. Season with salt and pepper to taste, and mix well until all ingredients are evenly combined.
In a greased 9x13 inch baking dish, spread half of the tortilla strips evenly along the bottom.
Layer half of the chicken mixture over the tortilla strips. Add another layer of tortilla strips followed by the rest of the chicken mixture.
Top the casserole with the remaining tortilla strips and spread the sour cream over the top. Sprinkle the remaining shredded cheese over the sour cream.
Cover the baking dish with aluminum foil and bake in the preheated oven for 25 minutes.
After 25 minutes, remove the foil and bake for an additional 15 minutes, or until the cheese is bubbly and golden brown.
Remove from the oven and let it cool for a few minutes. Garnish with fresh cilantro if desired before serving.