Ingredients:
- 1/4 cup dry white wine
- 1/4 cup white wine vinegar
- 1 large shallot, minced
- 2 tbsp fresh tarragon leaves, finely chopped and divided
- 1/2 tsp whole black peppercorns, crushed
- 3 large egg yolks, room temperature
- 1 cup unsalted butter, high-quality European style
- 1/4 tsp Kosher salt
- 1 pinch cayenne pepper
- 1 tsp fresh chervil, finely chopped
Instructions:
- In a small saucepan over medium heat, combine the white wine, white wine vinegar, minced shallots, crushed peppercorns, and 1 tablespoon of the chopped tarragon.
- Simmer the mixture until the liquid has reduced to approximately 2 tablespoons. Strain through a fine-mesh sieve into a small bowl, pressing the solids to extract all liquid; discard the solids.
- Add the 3 room-temperature egg yolks and 1/4 tsp salt to the bowl and whisk vigorously until the mixture becomes pale and slightly frothy.
- Place the bowl over a saucepan of gently simmering water (the water should not touch the bottom of the bowl). Whisk constantly for about 2 to 3 minutes until the yolks thicken enough to leave a trail. Note: If the bowl feels too hot to touch, lift it off the steam for a few seconds.
- Melt 1 cup of unsalted butter and keep it warm but not boiling. While whisking the yolks constantly, begin adding the butter in a very slow, steady stream. Start with just a few drops at a time until the sauce begins to look glossy and thick.
- Once all the butter is incorporated, whisk in the remaining 1 tbsp of fresh tarragon, 1 tsp chervil, and a pinch of cayenne. Taste the sauce; it should be rich but bright. If it is too thick, whisk in a teaspoon of warm water or extra lemon juice until it reaches a pourable, velvety consistency.