Potato Soup

4 tsp. margarine
1 onion, chopped
6 to 7 medium potatoes, cubed
3/4 tsp. garlic salt
salt and pepper
1 can cream of chicken soup
1/2 to 3/4 lbs. Velvetta
1 soup can of water

Saute onion in margarine. Add potatoes. Add enough water to barely cover potatoes. Add seasoning. Simmer until potatoes are tender. Add soup and cheese. Stir until cheese melts. Add enough water to desired consistency.