Makes about 1 cup.
12 Tbs. Unsalted Butter (1½ sticks)
3 Large Egg Yolks
2 Tbs. Freshly Squeezed Lemon Juice
½ tsp. Kosher Salt
¼ Cup Boiling Water
Pinch of Cayenne Pepper
METHOD:
Melt butter in a small saucepan over medium-low heat (keep warm until ready to use). Place egg yolks in heatproof bowl that fits snugly on the top of a medium saucepan. Fill the saucepan with 2 inches of water and bring water to a boil.
Whisk the egg yolks off the heat until they become pale yellow in color. Add in one teaspoon of the lemon juice and the salt and whisk until well combined. Gradually add in ¼ cup boiling water, whisking constantly. Now, place bowl on top of bain-marie and reduce heat to lowest setting. Whisking constantly, cook until the whisk leaves a trail in the mixture and sauce begins to hold its shape. Remove from heat.
Pour the warm melted butter into a glass measuring cup. Begin adding butter to egg yolk mixture, one drop at a time, whisking constantly. After you have added one tablespoon of the butter, you can add the rest in a little faster, but remember to whisk constantly. If the butter is added too quickly, the emulsion will be too thin or will “break.”
Once all of the butter has been added, adjust the seasoning with the remaining tablespoon of lemon juice and the cayenne pepper. If the sauce is too thick, thin it with a little more lemon juice. If not serving immediately, place sauce in a bowl over a pot of simmering water, removed from the heat.
