Open the oysters, keep the hollow shells:wash and dry them; put the oysters on a buttered dish, lightly peppered on it, no salt of course, heat the oysters in the oven without cooking them, as well as the shells.
Sweat the chopped shallot in a little butter, add your mushroom duxelles, adjust the seasoning, add the nutmeg.
Mix the hollandaise sauce with the chive sauce, cook gently for 5 minutes, sieve just before serving, add two spoonfuls of whipped cream.
Blanch the seaweed in boiling water:drain and divide on the bottom of four plates.
Place six shells on each plate, garnish with warm mushroom duxelles, arrange the warmed oysters in each shell and cover with the sauce, then pass under the salamander or the grill to glaze.
Garnish with finely chopped chives and sticks.
Dutch sauce:
Heat the cream in a saucepan until it simmers.
In another, add the egg, whisk it then add the cream spoon by spoon to the egg while mixing
When you have added 5 spoonfuls of cream, put the preparation on very low heat and continue to pour the cream until you run out, still stirring
Add the squeezed lemon, salt and pepper. Let it cook for a few minutes.
Chive sauce:
Finely chop the shallot and chop the chives.
Crush the peppercorns by placing it in a cloth and pressing firmly on it with a plate or a saucepan for example
Reduce the alcohol vinegar, crushed pepper shallot mixture by 3/4 for about 5 minutes and leave to cool off the heat
Add the crème fraîche to the cooled preparation, then add the chopped chives, salt the chive sauce at the end of the preparation.
Breton oysters from Prat-ar-Coum have an inimitable taste, you will find them among other things on the internet at
http://yfrog.com /5mhutres2d
And the duxelles recipe in the archives at http://www.recettes-hubert.com/?s=Merlan+bleu