Put the soaked beans, ham bone, water and vegetables in a large saucepan, together with the sage and parsley stems. Bring to the boil, skim any foam from the surface, partially cover, and simmer for 3 to 4 hours.
Remove the ham bone and the herb stems. Blend the soup until smooth, sieve, if you wish, and return it to the saucepan. Thin the soup, if you like, with ham or vegetable stock or water.
Tear up the herbs, and grind them to a paste in a mortar with the sea salt and pepper. Heat the cream in a separate pan and stir in the herbs until well blended.
Bring the soup to the boil, ladle into soup bowls, and swirl the sage cream on top. Serve immediately.
© 2000 Frances Bissell. All rights reserved.