Ingredients:

  Amount  Measure       Ingredient -- Preparation Method
--------  ------------  --------------------------------
   1      pound         dried green split peas -- rinsed and picked
                        -- over
   2 1/2  quarts        water
     1/4  cup           salt pork -- diced
     1/2  cup           leeks -- chopped
     1/2  cup           celery -- chopped
     1/2  cup           celeriac -- chopped (celery
                        -- root, optional)
     1/2  cup           onion -- chopped
   1                    bay -- (laurel) leaf
   2      teaspoons     salt
   1                    smoked ham hock or pig's knuckle -- (optional)
     1/2  pound         precooked smoked sausage -- such as kielbasa,
                        -- sliced into 1/4
                        -- inch rounds

Preparation:

Cook the salt pork for 5 minutes in a heavy soup pot over moderate heat. Add the vegetables and cook 10 minutes, stirring frequently, until tender but not brown. Add the water, peas, bay leaf, salt, and ham hock or pig's knuckle and bring to the boil. Skim the foam from the surface of the soup and simmer over low heat for two hours. Remove the ham hock or pig's knuckle, shred the meat and set it aside. Discard the bone and the bay leaf. Strain the soup, pressing the vegetables through the sieve, or puree in an electric blender. Return the soup, the reserved pork meat, and the sliced kielbasa to the kettle, and simmer for 5 minutes, until the sausage is warmed throw.