Once, wherever chestnut trees grew, the nuts were important food for the poor, and yet their taste is luxurious. This chestnut soup, one of my very favorite soups, presents its main ingredient beautifully. It happens to be French, although chestnut soups are made in many places. Chestnuts can be had only during the end-of-the-year season, of course, and the flavor of the soup depends on their quality — the best, when hot, have an aroma of honey — and on the clear flavor of the chicken stock. Along with that, milk is a light, traditional addition that respects chestnut flavor, but for years I’ve instead added cream, as below. Make your stock with a generous quantity of leeks, or reboil it with leeks before adding it to this soup.