This creamy, chilled soup is a version of the classic Vichyssoise, originally created by a French chef at the Ritz Carlton Hotel in New York to celebrate the opening of the roof gardens.

INGREDIENTS

Serve 4

25g/1oz/2tbsp butter 15ml/1 tbsp vegetable oil 1 small onion,

Chopped 3 leeks,

Slice potatoes,

Diced 600ml/1 pint/ 2 ½ cups hot vegetable stock

300ml/1 ¼ cups milk

45ml/3 tbsp single cream a litter extra milk (optional)

Salt and ground black paper

60ml/4 tbsp natural yogurt and snipped chives

To garnish

1 Place the butter and oil in a large microwaveproof bowl, then add the onion, leeks and potatoes. Cover and microwave on HIGH for 10 minutes, stirring halfway through cooking. Stir in the stock and milk. Microwave on HIGH for a further 5-8 minutes, until the potatoes are tender.

2 Puree the vegetables and liquid in a blender or food processor until smooth. Return the soup to the bowl, stir in the cream and season well.

3 Leave the soup to cool and then chill it for 3-4 hours, or until really cold. You may need to thin the soup down as it will thicken slightly on cooling.