To a small bowl whisk the melted butter and flour together.
To a large mixing bowl add the cream of chicken soup, onion, cheese, sour cream, and ham. Mix well. Stir the hash browns and pepper in.
Grease the slow cooker with non-stick spray then pour the hash brown casserole in. Drizzle the butter mixture over the top. Optional: sprinkle more shredded cheese over everything.
Cover and cook on LOW for 5-6 hours or HIGH for 3 hours. Enjoy!