Preheat oven to 375°F and grease a 9×13 baking dish.

Cook diced chicken in olive oil until no longer pink; season with salt, pepper, and garlic powder.

Parboil potatoes in salted water for 5-7 minutes, then drain.

Blanch broccoli florets in boiling water for 2-3 minutes and drain.

In a large bowl, mix chicken, potatoes, broccoli, cream of chicken soup, sour cream, half the cheese, onion powder, garlic powder, salt, and pepper.

Pour mixture into baking dish and top with remaining cheese.

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