Bearnaise

Ingredients

• 0.75 cup unsalted butter – cut into pieces
• 2 tablespoons shallot – finely minced
• 4 sprigs tarragon stems – lightly bruised
• 0.5 teaspoon black peppercorns – lightly crushed
• 0.25 cup white wine vinegar
• 0.25 cup dry white wine
• 1 tablespoon water
• 3 large egg yolks – at room temperature
• 2 tablespoons tarragon leaves – finely chopped
• 1 tablespoon chervil leaves – finely chopped
• 0.25 teaspoon fine sea salt

Instructions

1. Melt the unsalted butter in a small saucepan over low heat until fully melted and warm (120–140°F). Keep warm off heat.
2. Combine the shallot, tarragon stems, black peppercorns, white wine vinegar, and dry white wine in a small saucepan. Bring to a gentle simmer and reduce over medium heat until the liquid measures about 2 tablespoons and looks syrupy, 5–7 minutes. Remove from heat to cool slightly.
3. Prepare the tarragon leaves and chervil leaves by finely chopping them; reserve to finish.
4. Set up a bain-marie: bring about 1 inch of water to a simmer in a medium saucepan and place a heatproof bowl over it so the bowl does not touch the water. Strain the reduction into the bowl, pressing on the solids; add the egg yolks and the water. Whisk constantly over the gentle simmer until thick, pale, and tripled in volume, 3–5 minutes, forming ribbons and reaching 150–155°F.
5. Remove the bowl from the heat and very slowly whisk in a thin stream of it until fully emulsified, starting with drops and increasing to a steady thread, 3–4 minutes. Whisk in the fine sea salt.
6. Fold in the reserved herbs. Serve immediately, or hold warm for up to 30 minutes in a barely warm spot (120–130°F), stirring occasionally.