Lettuce soup

Ingredients :
600ml/1pt chicken stock
1 round lettuce, shredded
1 small onion, chopped
25g/1oz butter
1⁄2 teaspoon freshly grated nutmeg
300ml/10fl oz milk
1 egg yolk
2 tablespoons single cream
salt and freshly ground black pepper

How to make
- Bring the stock to the boil, add the lettuce and boil for 5 minutes. In a separate pan, sweat the onion in the butter for 3 minutes until soft.
- Pour in the lettuce and stock, and season with the nutmeg, salt and pepper. Simmer for 5 minutes until the onion is very soft. Purée in a blender or food processor, and return to the saucepan. Stir in the milk.
- Whisk the egg yolk and cream together. Whisk in a little of the soup, then pour back into the remaining soup and heat through, stirring all the while. Do not allow to boil or the egg will curdle. Serve hot.