Preheat oven to 375° Fahrenheit. Prepare the casserole dish by spraying it with cooking oil spray.
In a large bowl, mix together hash browns, chicken, green beans, 1 cup cheddar cheese, sour cream, soup, chopped onions, and pepper.
Pour hashbrown chicken casserole ingredients into the prepared casserole dish and top with the remaining shredded cheese.
Bake for 45-50 minutes, or until hot and bubbly and golden on top, and edges are puffy. Let cool 5-10 minutes before serving.
Notes
To make your own shredded chicken:Use a skillet with a tight-fitting lid, add chicken breasts. Cover with water and several generous pinches of salt or chicken broth.Bring to a boil, put on the lid, turn down the heat to simmer, and cook for 15 minutes. Let cool and shred the chicken.Leftovers will keep well for up to 4 or 5 days in the refrigerator. Let the casserole cool completely and transfer to a sealed container before placing it in the fridge.If you plan to make this dish in advance and freeze, I suggest you use a foil container: Not only is it freezer-safe, but the container can be safely used in the oven as well to reheat it.Prepare the casserole as directed, without baking, and refrigerate for up to 3 days.Or prepare casserole without baking in a freezer-safe container, cover with a layer of aluminum foil, and freeze for up to 3 months. Again, a foil casserole pan works really well here. Then bake from frozen (do not defrost) as directed, plus an extra 15 minutes or so until it's heated throughout and the cheese is golden.