Creating Ham And Potato Casserole is straightforward if you follow these simple steps:

1. Preheat Oven: Preheat your oven to 350°F (175°C).
2. Prepare Casserole Dish: Grease a 9×13 inch casserole dish with cooking spray or butter.
3. Mix Ingredients: In a large bowl, combine the frozen hash browns, diced ham, chopped onion, and shredded cheese.
4. Create Sauce: In another bowl, mix together the cream of mushroom soup, sour cream, milk, garlic powder, onion powder, salt, and pepper until smooth.
5. Combine: Pour the soup mixture over the hash brown mixture and stir until everything is well combined.
6. Transfer to Dish: Spread the mixture evenly in the prepared casserole dish.
7. Add Topping: If desired, sprinkle breadcrumbs on top for a crunchy finish.
8. Bake: Place in the preheated oven and bake for 45 to 60 minutes or until the casserole is bubbly and golden on top.
9. Cool Down: Once done, remove from the oven and let it cool for a few minutes.
10. Garnish: Sprinkle with fresh parsley before serving for added color and flavor.