Savory ham and cheese hash brown casserole with cheddar and swiss cheeses, diced ham steak, and topped with fresh green onions.
Preheat the oven to 350°F and set out a 9x13 casserole dish.
In a large mixing bowl, add the shredded swiss cheese, shredded cheddar cheese, cream of chicken soup, chopped onion, sour cream, melted butter, garlic powder, salt, pepper, and mustard powder. Stir to mix everything together.
Add the diced ham steak to the mixing bowl and stir to coat the ham pieces in the cheese mixture.
Fold the thawed hash browns into the cheese mixture, ensuring the hashbrowns are completely coated in the cheese mixture.
Transfer the cheesy hashbrowns to the casserole dish and use a silicone spatula to spread them into an even layer.
Bake the ham and cheese hash brown casserole in the oven for 1 hour, until the edges just begin to corn. Once out of the oven, let the casserole cool for about 5 minutes.
Garnish with thinly sliced greens and serve warm. Enjoy!