Nanny's Irish Leek Soup

Ingredients:

4 Leeks, cut into 1/2" slices
1 Medium diced onion
4 Med. potatoes peeled & diced
4 c Chicken broth
1 c Sour cream
1 1/2 tb Butter or margarine
Pepper to taste

Method:

In a large saucepan melt butter and add leeks and onions.
Cook, covered, until vegetables are tender, stirring occasionally.
Add potatoes and broth and simmer covered for 40 minutes.
Add sour cream and heat to serving temperature but do not boil.
Season with pepper and serve at once.