Pork and Water Chestnut Sausage Wontons in Watercress and Shiitake Mushroom Soup

In the annals of folk medicine, watercress soup is said to be good for soothing a dry throat or for when a general system-cleansing tonic is needed. Here, the nip and pep of watercress infuses chicken broth made rich with slivers of shiitake mushroom and plump sausage-filled wontons to produce a new take on wonton soup that is both healthful and delicious. Hydroponic watercress, meaning watercress grown in water and without soil, closely resembles watercress you might pick alongside a running stream in spring, but it has finer, more delicate stems and far less dirt and sand on its leaves. It is often available year-round in supermarket produce sections.