Cream of Lettuce and Pea Soup

It sounds odd with cooked iceberg lettuce, but is actually one of my favourite soups of all time.  Serve either hot or cold. Adapted from Gretta Anna Teplitzky

250g frozen baby peas
1 large potato, peeled and sliced
1 onion, sliced
1 iceberg lettuce, cut into 8 pieces
750mls chicken stock
Juice ½ lemon
300mls cream
2 tablespoons chives
Mint from 4 sprigs
Place stock, onion, potato and lemon juice into a saucepan and simmer for 15 mins, or until potato is tender.
Add peas and lettuce and simmer just until the lettuce is soft.
Puree in a blender, then pass through a seive.
Add cream and serve hot or chilled.