Saute the chopped leeks,chopped onions, and 1 clove of minced garlic in margarine until translucent. Add the chicken broth and the peeled and diced potatoes to the mixture, and cook until potatoes are tender.
Puree mixture in blender half at a time. Place in large soup pot and add cream,salt and pepper.Cook stirring occasionally until hot. Garnish as desired and serve.