Use a double boiler and place 1/2 cup of water in it. Heat the water, but do not boil.
Melt the butter in a bowl in the microwave. Separate the eggs and add the yolks to the top of the double boiler. Add the salt, cayenne pepper and lemon juice.
Place the eggs over the double boiler, insert the electric mixer and mix well. Wait one minute and add the butter slowly, continuing to use the mixer. Add all of the butter, continue mixing and suddenly it will thicken and be ready for use. If it is too thick take the tablespoon and add a tablespoon of hot water from the double boiler, maybe two, no more. Its ready.