In a large mixing bowl, combine the shredded cheddar cheese, cream of chicken soup, sour cream, thawed hash browns, chopped onion, and melted butter. Mix well.
Season with salt and pepper to taste.
Transfer the mixture to a greased baking dish.
Bake in the preheated oven for 45 minutes, or until the top is golden brown and the casserole is bubbly.
Let it cool for a few minutes before serving.
Notes:
This casserole is perfect for family gatherings or potlucks. You can also add cooked chicken or ham for extra protein.