Directions

1. 1. Cut the butter in small cubes and put in a bowl.
2. 2. Set the bowl in ice water. (The butter should be very cold; otherwise it might melt too quickly and the sauce might break.)
3. 3. Place shallots in a medium stainless-steel saucepan.
4. 4. Add the white wine and wine vinegar. Boil the liquid over high heat until it is reduced to a scant 1 tablespoon.
5. 5. Just before serving, add the pieces of butter to the pan, 1 at a time, whisking well after each addition, until it has all been used. (The sauce should be fairly thick.)
6. 6. Add a little lemon juice to the sauce to taste. Season with salt and white pepper.
7. 7. If you're a purist, you'll want to strain the shallots out of the sauce before serving.
8. 8. Some chefs prefer to leave the shallots in; if you're among them, you might also want to mix finely minced parsley or tarragon into the sauce.
9. 9. And some chefs like to bolster the sauce with a little crème fraiche just before serving it.