3/4 lb. leeks (about 3 large)
1/2 c. butter
1 qt. water
1 qt. chicken broth
2 lbs. potatoes, peeled and diced
Salt and white pepper
1/2 c. heavy cream

Chop leeks finely, including tops. Melt 1/4 cup butter and add leeks. Cover and cook about 5 minutes. Add water, broth, potatoes, salt and pepper to taste. Simmer 45 minutes or until potatoes and leeks are very soft. Puree the soup in blender or sieve, return to pot. If too thick add more chicken broth. Just before serving add remaining 1/4 cup butter and heavy cream.