Broccoli Casserole

1 Onion chopped
1 cube Margerine or Butter
1 Bag of Broccoli chopped
1 can Cream of Mushroom Soup
2 Cups cooked Rice
1 bottle of Cheese Whiz
1 can water (soup can)

Saute Onion in margerine. Add rest of ingredients. Cook until it boils and serve.