In a small sauce pan: melt 120g butter: skim & keep the top butter into a measuring cup
warm a sauce pan: below 60c. setting 1 wish 2 egg yolks & 1 tbsp cold water: until creamy add 1 tbsp lemon &pinch of salt
slowly add 125g butter: whisk constantly if too thick, add 1tbsp water at a time. season with salt & cayenne pepper
quick version: high heat, swirling melt butter: hot and foam in a cup blend together 1 eggs yolk 1tsp water 1 tsp lemon pinch of salt slowing add 113g butter