Preheat oven to 350°F (175°C) and spray a baking dish with nonstick cooking spray.

Season chicken breasts with salt and pepper. Cook in a skillet over medium heat until golden brown on both sides (6-7 minutes each side). Remove from heat and let cool slightly before shredding.

In a large mixing bowl, combine shredded chicken, chopped vegetables, mayonnaise, sour cream, garlic powder, onion powder, and mix well.

Transfer the mixture to the prepared baking dish and sprinkle shredded cheese on top.

Bake for 25-30 minutes until bubbly and golden brown. Let rest for 5 minutes before serving.