Lamb Meatball, Garbanzo Bean, Lentil, and Tomato Soup

Called harira in Morocco, this hearty lamb, garbanzo bean, and lentil soup is traditionally served in the evening, after everyone has fasted all day during the holy month of Ramadan. The soup is seasoned with harissa, a fiery red-chile-and-spice paste found in colorful tubes and small cans in grocery stores and online. The spiciness of harissa varies from brand to brand; taste it first and add it to the soup according to your heat tolerance. Though this soup is usually made with chun