10 tablespoons unsalted butter, cut into 1 tablespoon pieces
2 teaspoons fresh lemon juice
1/2 teaspoon Kosher salt
1/8 teaspoon cayenne
Directions
Fill a medium saucepan with 1-inch of water and bring to a simmer over medium heat. Reduce heat to low. Place egg yolks in a medium bowl and whisk until they lighten in color, about 1 minute. Place bowl with eggs over saucepan with simmering water and whisk constantly until thickened and doubled volume, about 3 to 5 minutes. Remove bowl from from saucepan with water and whisk in butter 1 tablespoon at a time. Whisk in lemon juice, salt, and cayenne. Use immediately or keep warm, covered, over double broiler over very low heat for up to 30 minutes.