Heat olive oil in a pan on medium heat, add in asparagus, salt and pepper. Heat for about 3 mins then set aside.
Separate 4 egg yolks. Whisk yolks. Set aside.
Whisk a yolk and a TBSP of lemon juice in a metal bowl.
Boil water in a medium saucepan. Hold the metal bowl over the boiling water heating the bowl, constantly whisking. Gradually add in the butter. Whisk until thick. If too thick, add water.