In a small saucepan over medium high heat bring white wine vinegar, shallots, peppercorns, tarragon, chervil to a boil and reduce by 9/10th, strain, set aside.
In a medium bowl over simmering water whisk egg yolks until light and fluffy. Stir in vinegar reduction. Add butter in cubes, whisking until thick.
Taste sauce and season to taste.
Garnish sauce with chopped chervil and tarragon
Recipe Courtesy of Dan Laytham