This recipe is one of those "to taste" recipes, meaning that you add the ingredients to your taste preference.
Peel the hard boiled eggs and slice in half.
Put the yolks into a bowl and mash with a fork.
Add in softened butter, lemon juice, and cayenne pepper to taste. Sometimes, I like more heat, and sometimes, I like more lemon. It is completely up to you.
Mash it all together into a hollandaise paste, then scoop it back into the egg whites.