1 oz (30 g) butter
1 small onion, chopped
5 oz (145g) spring onions, white parts only, chopped
8 oz (225g) potatoes (2 medium-sized), peeled and chopped
1 pint (600ml) chicken stock
12 floz (360ml) single cream
salt and white pepper
2 tablespoons lemon juice
chopped spring onion greens or fresh chives, to garnish
2. Add the potatoes and the stock. Bring to the boil, then cover again and simmer over moderately low heat for about 30 minutes. Cool slightly.
3. Puree the soup in a blender or in a food processor.
4. if serving the soup hot, pour it back into the pan. Add the cream and season with salt and pepper. Reheat gently, stirring frequently. Stir in the lemon juice.
5. If serving the soup cold, pour it into a bowl. Stir in the cream and lemon juice and season with salt and pepper. Cover the bowl and chill for at least 1 hour.
6. sprinkle with spring onion greens or chives before serving.