Cream Of Leek Soup

1 lb. leeks

1/2 lb. butter

1 c. flour

1 qt. chicken stock or 4 bouillon

cubes 1 qt. half and half

1 tsp. salt

1/4 tsp. pepper

Clean leeks and cut into 1/2" pieces. Steam in 1/2 cup water until tender. Do not drain. Set aside. Melt butter in saucepan. Add flour to make a roux. Cook 2 to 4 minutes. Add chicken stock, stirring with wire whip, bring to boil. Turn heat on low and add remaining ingredients. Do not boil. Add 1 cup diced, cooked potatoes and 1 cup diced, cooked ham, if desired.