Creamy Cheesy Chicken Casserole

2 C. dry shell macaroni
3 C. cubed cooked chicken or turkey (3 to 4)
1/2 lb. cubed yellow cheddar cheese
Crushed potato chips or buttered crumbs for topping

Sauce:
1/3 C. butter or margarine
2/3 C. flour
3 C. chicken broth (add milk to make 3 C. if not enough broth)
1 can cream of mushroom soup
1 small can mushroom pieces drained, optional
1 small chopped onion
Generous dash garlic powder
Salt and pepper as needed

Preheat oven to 350° F. Cook macaroni according to directions and drain. Stir together chicken, cheese and sauce ingredients. Pour into a shallow baking pan. Bake until bubbly, about 35 - 40 minutes. During the last 5 minutes in oven, sprinkle buttered crumbs or crushed potato chips over top of casserole. Return to oven for 5 minutes, being careful not to let topping get too done.