Combine 3 tbsp White Wine Vinegar, 3 tbsp Dry White Wine, 2 tbsp finely chopped Shallots, 1 tsp crushed Black Peppercorns and a small handful of bruised Tarragon leaves in a small saucepan.
Bring the mixture to a gentle simmer and reduce over medium‑low heat until about 2–3 tablespoons of liquid remain and the flavors are concentrated, about 6–8 minutes; then strain the reduction into a bowl, pressing on the solids to extract flavor and discarding the solids.
In a heatproof bowl whisk together 3 Egg Yolks and 1–2 teaspoons Water until smooth, then whisk in 1 tablespoon of the warm reduction to temper the yolks.
Set the bowl over a pan of barely simmering water (bain‑marie), making sure the bowl does not touch the water, and whisk constantly until the yolks thicken to a ribbon‑coating consistency.
Remove the bowl from the heat and, very slowly at first, drizzle in 10–12 tbsp warm Unsalted Clarified Butter while whisking constantly to form a thick, glossy emulsion; continue adding the butter in a steady stream until fully incorporated.
If the sauce becomes too thick, whisk in a teaspoon or two of warm water or a little more of the reserved reduction to loosen it; if it breaks, whisk in a teaspoon of cold water to help bring it back together.
Season the béarnaise with a pinch of Fine Sea Salt and freshly ground pepper to taste, then fold in a generous tablespoon each of finely chopped fresh Tarragon and Chervil.
Keep the sauce warm (not hot) over very low heat or in a thermos until ready to serve; béarnaise is best served immediately alongside grilled steak, fish or steamed vegetables.
