The dish that changed something · c. 1981
Potato purée
Joël Robuchon · 1945–2018 · Jamin, Paris; later L’Atelier, worldwide
Ratte potatoes, passed fine, with something near a quarter of their weight in butter. It made a side dish the reason to book the table, and reset what a cook is allowed to mean by simple.
Why it works
Ratte flesh is waxy and low in starch, which is why it takes that much butter without turning to glue; passed fine and beaten warm it emulsifies instead of developing.