Crock Pot Potatoe and Ham casserole

4 red potatoes, sliced
2 red onions, finely chopped
1 1/2 pounds cubed ham
1 can condensed cream of celery soup, diluted according to can directions
2 tablespoons flour
Shredded cheddar cheese

Combine all of this into a crock pot except for Cheese(save that for when it is done). Add salt and pepper to taste. Turn it on low and walk away for eight hours. Add a quarter of a cup of water for every additional two hours you intend to cook it.  Sprinkly with Cheese when done :)