1) Heat up the butter into a pot and add the leek finely sliced. Season well and allow to sweat off for 5 minutes.
2) Add the flour and stir for a little while. Add 1.5 litre of cold water.
3) Bring to the boil and add the cauliflower, check the seasoning and simmer for an hour.
4) Blitz your soup and pass it through a fine sieve (if you wish).
5) Mix the cream and the egg yolks. Then add a ladle of soup into the mixture stir well and pour the lot into the rest of the soup, off the heat. Stir well. Careful now, your soup cannot boil any more. Otherwise it will split. So, keep your soup in a bain-marie (double boiler) until serving time.
Place few florets of cauliflower in each bowls and pour some hot soup over them. Success guaranteed!
credits photo : ©Richard Villalon- fotolia