Used to make it nightly when I worked in a restaurant Big stainless bowl, large wire whisk and a small ladle with the butter. And forearms like a longshoreman. Got better and better at it too. I could tell when I was breaking, curdling or rushing. It's a time consuming and high effort sauce, but when it's good, it's extraordinary and you can then fraction it out and make so many other sauces or variations.