Grandma's Scalloped Potatoes

5 to 6 potatoes, peeled and sliced

1 onion, chopped

1/2 cup hot water

1 can cream of mushroom soup

2 chicken bouillon cubes

3 tablespoons butter or margarine

1/2 cup shredded cheese

Preheat oven to 350 degrees.  Put potatoes and onions in casserole dish.  In separate bowl, mix together water, soup, and bouillon cubes.  Pour over potatoes and mix slightly.  Bake for 1 1/4 hours.  Cover with cheese and bake another 15 minutes.