Funeral Potatoes

2 lbs frozen hash brown shreds, thawed 
1/4 cup butter
2 (10 3/4 ounce) cans condensed cream of chicken soup
1 pint sour cream
1/2 tsp. salt
1/4 tsp. pepper
1/2 cup onion, finely chopped
1 tablespoon butter
1.5 cups marbled cheddar cheese, grated, firmly packed
1 1/2 cups corn cereal (Corn Flake or Corn Chex work well), crushed
3 tablespoons butter, melted