Fermented Watercress Soup

Do not be put off by the bizarre sound of this soup: it is quite interesting and delicious. It is a potato-based soup, made on the pattern of a vichyssoise, and with the interesting addition of “aged” cress. My thanks to Mr. Shi, who first had this soup in 1918 in Chicago, and remembers it vividly now.

Dried watercress is available in Chinese markets.