Preparation time: 20 minutes
Cooking time: 25 minutes

50g/2oz butter
500g/1lb potatoes, peeled and roughly chopped
500g/1lb leeks, sliced
500ml/1 pt chicken stock
250ml/½ pt single cream
2 x 85g/3oz packs watercress (leaving some sprigs for garnish)
salt and pepper

Melt the butter and gently fry the vegetables for 5 minutes. Add the chicken stock, bring to the boil and simmer for 20 minutes or until the potatoes are soft. Cool a little and add the cream and watercress. Liquidise until smooth. Season well and either heat through for a hot soup or chill for 3-4 hours for cold soup.