Prepare dried beans by soaking them in cold water for 8-10 hours, then drain and rinse (I do this the night before).In large pan heat oil and sauté celery, carrots, onions and garlic until tender.Add chicken stock, ham bone and ham. Transfer to larger pot if necessary.Add beans, parsley, thyme and pepper.Bring to a boil, then reduce heat and simmer covered for 2-3 hours.Chop up large pieces of ham before serving