Instructions

1. Place the white wine vinegar, shallot, dried tarragon and black peppercorns in a small saute pan. Bring to a fast simmer over medium heat and cook until the vinegar is reduced and pan is almost dry. There should be about a teaspoon of liquid left.
2. Remove from the heat, add the water and strain through a fine mesh strainer over the top part of a double boiler pressing on the solids to remove all liquid.
3. Add the egg yolks and whisk to combine.
4. Bring an inch of water in a double boiler to a boil and reduce heat to low keeping at a low simmer.
5. Place the pan with the yolk mixture over the bottom part of the double boiler and whisk constantly until the mixture begins to thicken. Keep an eye on the heat to be sure that the water in the bottom does not boil. If it seems to be getting too hot, remove from the heat for a moment to cool down.
6. When the mixture has started to thicken slowly add the melted butter constantly whisking to keep the sauce in suspension.
7. After all of the butter has been added and the sauce is smooth and thick turn off the heat.
8. Add the fresh tarragon, lemon juice and salt & pepper to taste.