First to clarify the butter, add the butter to the pan and leave it on low fire until it has melted and has white foam on the top or bottom. Take off white foam and strain through a muslin cloth.You will be left with a clear yellow mix that looks like oil. Leave it aside to cool down completely
On a bowl add the egg yolks, spicy sauce, salt and pepper and vinegar and mix well until well combined. Then place the bowl on a pot of boiling water (double boiler) and whisk until it is thick and creamy. (Note: eggs can get scrambled very easily so keep an eye out),
Once it has thickened take it out of the fire and add the clarified butter little by little while whisking ( If the sauce split, check above article on how to fix it)
Once finished, if the mixture is too thick add 2 tbsp of boiling water and whisk well until combined.