Instructions:
Preheat Oven: Preheat your oven to 350°F (175°C). Grease a 9×13-inch baking dish.
Mix Filling: In a large bowl, combine cream of chicken soup, sour cream, mayonnaise, garlic powder, onion powder, salt, and pepper. Mix well.
Add Ingredients: Add cooked chicken, frozen vegetables, and shredded cheese to the mixture. Stir until combined.
Assemble Casserole: Pour the mixture into the prepared baking dish.
Prepare Topping: In a small bowl, combine crushed cornflakes (or crispy fried onions) with melted butter. Stir to coat.
Top and Bake: Sprinkle the topping over the casserole. Bake for 30-35 minutes, or until bubbly and golden brown.
