Traditional Irish Potato Soup from Dublin

6 med. potatoes peeled and chopped
2-3 stalks celery chopped
1 large onion chopped large pieces
corn (optional)
garlic salt
salt and pepper
1 c. butter (only pure butter, 2 sticks)
Milk

Boil potatoes, onion and celery with water to cover till crisp tender. Drain off water and add milk to cover potatoes and add butter. Add optional corn. Sprinkle garlic powder to taste and salt/pepper. I am sure light butter will work....