Make the reduction: Chop the shallots in a small chopping machine, grating the sides of the bowl. With the bottom of a pan, crush the peppercorn pressing up and down. Add to the shallots. Chop the tarragon leaves without the stems. Put in the chopped shallots, peppercorn and tarragon leaves. Moisten with white wine and white wine vinegar. Stir and bring to a boil on medium heat. Reduce the Béarnaise reduction to almost dry. Let it cool.

Make the sabayon: Warm the clarified butter in a saucepan on the low heat. Place the egg yolks in a bowl with 2 tablespoons cold water. Add the cool reduction to the yolks and water mixture. Whisk and place on Bain Marie over medium heat. Using the second speed of your electric whisker, whisk for at least 5 minutes. Make sure that the water is simmering, not boiling. Keep whisking over the heat until the sabayon gets thick. This is called the ribbon stage. When desired thickness is obtained, remove from heat. Gradually pour in the clarified butter, whisking continuously. Chop the parsley, or chervil if available. Taste the sauce and season with salt and a pinch of cayenne pepper.