Beverly's Breakfast Potatoes

Is there one of those recipes that is simple, rich and oh so yummy that is so comforting?  My mother-in-law's Breakfast Potatoes is a dish like that for me.  She makes them for breakfast sometimes and also sometimes for dinner.  Whenever they are made, they are so yummy.  The recipe is pretty simple - but sometimes it's the simple recipes that are the best.
How can you go wrong with potatoes, onions, cream of mushroom soup and cheese?  Ok a few other things too - but pretty standard fare, but really good.

Beverly's Breakfast Potatoes
1 large bag frozen Hash brown Potatoes (2 lbs)
1 can cream of mushroom soup
2 cups cheddar cheese
1 onion chopped finely
1/2 cup melted butter
1 8 oz carton sour cream
1 tsp salt
1/2 tsp pepper
1 tsp season salt

Mix all ingredients n large mixing bowl.  Pour into 9 x 13 casserole dish and bake at 350 for 45 minutes or until bubbly and hot.   Can be frozen ahead.