Adapted from: "Vegetable Soups from Deborah Madison's Kitchen". "This soup can be served hot, tepid, or chilled-- its flavors perhaps optimal at room temperature. It won't win any beauty contests--eggplant makes everything a bit dull looking--but leaving some texture in the soup helps, along with the swirl of yogurt and a perfect sprig or two of cilantro. In any case, the flavors will win kudos, and that's what counts."