Watercress Soup

• 2 bunches watercress
• 2-3 large potatoes
• 1 onion

Put the potatoes and onion, peeled and roughly chopped, into a large pan. Add cold stock, bring to the boil and simmer for 15-20 minutes; now throw in the washed watercress, stalks and all, and cook until it is tender but still a good green. Sieve all this, helping it through the mouli by moistening with the milk. If you want a green-flecked soup, use a coarse disc for your mouli; if a uniform