1. Fit the crock pot with a plastic liner for easy cleanup.
2. Add the hash browns to the crock pot. Top with diced ham, salt, black pepper, and garlic powder.
3. In a bowl, combine the cream of mushroom soup and milk. Whisk together until well combined.
4. Pour the soup mixture over the hash brown and ham mixture. Sprinkle with shredded cheese and stir to combine. Cover with the lid and cook on high for 2-3 hours or on low for about 4 hours, until the potatoes are tender and the cheese is melted.
5. Serve warm, garnished with sliced green onions.