Preparation time: 25 minutes plus 8 hours chilling time
Cooking time: 30 minutes

1 onion, roughly chopped
25g butter
600ml chicken stock
250g potatoes, peeled and diced
2 x 85g bags watercress
4 pears, peeled, cored and diced
50ml cream
a little milk
salt and pepper

In a large pan, sweat the onion in the butter until soft but not brown, about 10 minutes. Add the stock and potatoes, cook until the potatoes are soft, approx. 15-20 minutes. Add watercress and diced pear for the last five minutes of cooking time. Liquidise and add the cream and a little milk if the soup seems too thick. Season, cool and cover, then chill in the refrigerator for at least 8 hours. Check seasoning before serving.