Ingredients

  • 2 tablespoons tarragon vinegar
  • 2 tablespoons dry white wine
  • 1/4 cup very finely chopped shallot
  • 1/4 teaspoon ground black pepper, more if desired
  • 1 tablespoon finely chopped tarragon leaf
  • 3 large egg yolks
  • 1 tablespoon water
  • 1/2 - 3/4 cup unsalted butter, very soft (I've always used 1 1/2 sticks)
  • coarse salt
  • pepper, if desired
  • lemon juice, if desired

Method

  • Combine vinegar, wine, shallots, black pepper, and 1 1/2 teaspoons tarragon in a small saucepan.
  • Cook over medium heat until reduced to 1 tablespoon, 5 to 10 minutes.
  • Add egg yolks and 1 tablespoon of water to reduced vinegar mixture.
  • Whisk until thick and pale, about 2 minutes.
  • Set pan over moderately low heat and continue to whisk at reasonable speed reaching all over bottom and insides of pan, where eggs tend to overcook.
  • To moderate heat, frequently move pan off burner for a few seconds, then back on.
  • As they cook, the eggs will become frothy and increase in volume, then thicken.
  • When the bottom of the pan is visible in the streaks left by the whisk and the eggs are thick and smooth, remove from heat.
  • By spoonfuls, add soft butter, whisking constantly to incorporate each addition.
  • As the emulsion forms, add butter in slightly larger amounts, always whisking until fully absorbed.
  • Continue incorporating butter until sauce has thickened to consistency desired.
  • Season with salt, remaining 1 1/2 teaspoons chopped tarragon and, if desired, pepper.
  • Add a few droplets of lemon juice if necessary.