Wash and boil
the potatoes in their skins in salted water. When cooked, peel
immediately and cut into dice. Wash and pick over the watercress. Wash
and slice the celery and cucumber. Cut the cheese into cubes and roughly
chop the nuts. Line a salad bowl with the watercress and mix all the
other ingredients in the middle. Pour over a vinaigrette dressing and
serve.