Step 1

Combine the egg yolks and lemon juice in a small saucepan, whisking vigorously until blended. Cut the butter into small cubes. Add half of the butter to the pan.

Step 2

Place saucepan over low heat, stirring constantly with a whisk, until the butter melts and the mixture thickens, about 5 minutes. Remove from the heat.

Step 3

Add the remaining butter and whisk vigorously until the butter melts and is fully incorporated, creating a smooth, velvety sauce. Stir in the salt and cayenne, and serve immediately.