It is also extremely delicious made with spinach instead of watercress.
Sophie Blue Rimmed Soup Plate (Set of Four), £62.00
400g fresh watercress cleaned
1 onion peeled and chopped
3 leeks, cleaned, trimmed and chopped
2 ribs of celery, cleaned and chopped
1 tbsp plain flour
600ml good chicken stock
300ml double cream
A grating of nutmeg
Pour 500ml water into a pan, add salt and bring to the boil.
Dump in the watercress and move it about with a spoon until it is all submerged in the water.
Leave to boil for 5 minutes.
Remove from the pan from the heat and allow the watercress and water to cool.
Meanwhile, heat another large pot on a low to medium heat, add the butter, onion, leeks and celery and gently sauté for ten minutes.
Sprinkle the flour into the onion pot and stir for a couple of minutes, then slowly add the stock, a ladleful at a time, stirring as the sauce thickens.
Once all the stock has been incorporated, leave to bubble for five minutes.
Return to the watercress, which should be cool, and pour it, water and all, into a blender.
Whiz until smooth.
Next, pour the onion mixture and the cream into the blender with the watercress and whiz again until velvety.
Return the soup to the pot, season with salt and nutmeg, heat through and serve.