Chop the fish in a food processor. Mix with the four egg yolks, the crème fraîche and the butter. Add the lemon juice, parsley, a pinch of salt and a twist of pepper.

Butter and flour the soufflé molds. Whip the egg whites until stiff and gradually fold into the preparation, taking care to maintain the volume. Fill the molds to just below the tops and bake for 20 minutes at 180°C and then turn the heat up to 200°C for the last five minute to brown the tops.

For the sauce, destalk the watercress and wash the leaves. Place them in a pan with the Chablis and heat over a medium flame. When the mixture has reduced somewhat, blend and then strain.
Add the double cream and boil to reduce. When it is a little less fluid, add the whipped cream and season.

Unmold the soufflés, and arrange on plates surrounded by some watercress sauce.

 Chef's tip

Add a little salt and lemon juice to the egg whites before whipping. They will be stiffer and keep their fluffiness when folding into the other ingredients. Careful temperature control is also important for a successful soufflé. The oven must be hot before they go in, so set the temperature to more than 180°C for a few minutes beforehand, and then return the temperature to 180°C just before adding them. Do not open the door while cooking the soufflés to keep the heat in.