Hash Brown Potato Casserole

1 (26-oz) package frozen shredded hash brown potatoes
1 (10 3/4 oz) can reduced fat, reduced sodium cream of chicken soup, undiluted
1 1/3 cups fat-free milk
1/4 cup finely chopped onion
1 tablespoon butter or margarine, cut into small pieces
3/4 teaspoon pepper
1/2 teaspoon salt
Cooking Spray
1 cup (4 oz) shredded Cheddar cheese

Spray crockpot with cooking spray.  Place first 7 ingredients into CP; stir well.  Cover with lid; cook on high setting 1 hour.  Reduce to low setting and cook for 4 to 5 hours.  Add cheese, stirring gently.  Cover and cook another 30 minutes.  Yield:  8 servings (3/4 cup servings).