Traditionally, this soup has butter and thick cream added to it, but our version is much lighter and allows the subtle flavour of the vegetables to come through. This is the perfect choice for those that prefer a less strongly flavoured soup.
1. Peel and finely chop the onion. Place in a large saucepan along with the bay leaves and 142ml/½ pt of the stock. Bring to the boil, cover and simmer for 5 minutes.
2. Meanwhile, peel and finely dice the potatoes. Trim the leek and slice lengthwise. Rinse under cold water to remove any trapped earth. Shake well to remove excess water and then shred.
3. Add the potato and all but a few shreds of the leek. Pour in the remaining stock and season well. Bring to the boil, cover and simmer for 25 minutes until tender.
4. Discard the bay leaves and transfer the mixture to a food processor or blender. Blend until smooth and return to the saucepan.
5. Blend in the fromage frais and reheat gently without boiling. Adjust the seasoning if necessary. Ladle into warmed soup bowls, sprinkle with black pepper, reserved shredded leek and chopped chives.