Gather all your ingredients: egg yolks, salt, pepper, lemon juice, and butter.
Melt the unsalted butter in a small saucepan over low heat and let it cool slightly.
In the blender, combine egg yolks, salt, cayenne pepper, and lemon juice. Blend on medium for about 30 seconds.
While blending, slowly drizzle in the melted butter until the sauce is thick and creamy.
Taste and adjust seasoning with more salt or lemon juice if desired. Add warm water if a thinner consistency is needed.
Serve immediately, drizzling over your favorite dishes.
