Here's one from my church cookbook. I've never made it but it is a staple at our ladies' brunches.
Hash Brown Casserole
1kg. bag of frozen hashbrowns
1 can cream of chicken soup
1 cup grated cheddar cheese
1 cup grated Monterey Jack cheese
2 tbs. chopped onion
1 tsp. salt
1/2 cup milk
topping: 2 cups crushed cornflakes
1/2 cup melted butter
Mix cornflakes and butter together. Set aside. Mix remaining ingredients in a bowl. Pour potato mix into a greased 9x13" pan. Spread corn flake mixture on top of potato mixture. Bake at 350' for 1 hour.
note: You can substitute the soup for cream of mushroom or cream of celery. Optional ingredients such as cubed sausage, cubed ham, diced green peppers or sliced mushrooms can be added.
eta: I just read your last post so I'm not sure if the previous recipe would work for you. My mom makes a baked potato casserole with diced potatoes, olive oil and diced green peppers. When it is nearly done baking she sprinkles with shredded cheese. Ymmm...
Not sure how either of them would work in the crock pot.