Shell the fava beans and set aside. In a large pot heat the olive oil and add the green onions. Sauté for 3 to 4 minutes on medium heat. Add the chicken or vegetable stock along with the fava beans. Bring to a boil and turn the heat to low. Simmer beans and stock until the fava beans are tender (about 30 to 40 minutes). Add the milk and heat the mixture well. In a food processor, pour the bean and stock mixture into a food processor. Puree beans. Return the mixture to the soup pot and add the sea salt and black pepper. Heat the soup through but do not boil. Ladle soup into serving bowls and add a tablespoon of yogurt on top along with a sprinkling of chives. Makes 4 servings.
