Béarnaise Sauce

Bahan-bahan (1 porsi)

• 3 tablespoons finely chopped shallots, (from 2 shallots)
• 2 tablespoons finely chopped fresh tarragon leaves, (divided)
• ¼ cup white wine vinegar
• ¼ cup dry white wine
• 12 tablespoons (1½ sticks) unsalted butter
• 3 large egg yolks
• ¼ teaspoon salt
• Freshly ground black pepper