In a jug, combine your egg yolks, lemon juice, hot water, and a dash of salt and pepper.
Whizz everything together with your trusty stick blender until smooth.
Gradually pour in the hot melted butter while keeping your stick blender on. This will help emulsify the sauce and make it creamy.
If the sauce is too thick for your liking, just stir in a bit more warm water to get the perfect consistency.
