1) Bring the leeks, potatoes and water to the boil in the saucepan. Salt lightly, cover partially, and simmer 20-30 minutes, or until the vegetables are tender.

2) Pure the soup if you wish. Taste, and correct seasoning.

3) After chilling the soup, you may wish to stir in a little more cream. Taste carefully again, and correct the seasoning.

4) Top each serving with a sprinkle of chives or parsley and a drizzle or dollop of crme frache.