It's surprising but true: Joel Robuchon won his Michelin stars with, of all things, mashed potatoes. When he first prepared his soon-to-be signature dish at Jamin in Paris in the early 1980's, he stunned a world that was only familiar with grandma's satisfying but ordinary mashed spuds. Since then, Robuchon's incredibly rich potato purée has become so popular that customers demand it at every one of his restaurants. The key to the dish is to keep the potatoes hot as you mix in so much chilled butter—a pound for every two pounds of potato—that it takes vigorous and constant stirring to keep them smooth and silky.
- 2 lb. yellow-fleshed potatoes, such as yukon gold, unpeeled
- Kosher salt, to taste
- 1⁄4 cup milk
- 1 lb. unsalted butter, cubed and chilled
Boil potatoes in an 8-qt. pot of salted water until tender, about 25 minutes. Drain potatoes and set aside to let cool slightly. Meanwhile, bring milk to a boil in a 1-qt. saucepan; remove from heat, cover, and set aside.
Peel potatoes and pass them through a food mill into a 4-qt. saucepan set over medium-low heat. Using a rubber spatula, turn potatoes frequently until they take on a drier, fluffier consistency, 2–3 minutes. Reduce heat to low. Working in batches, vigorously stir in the butter until mixture is creamy. Whisk in warmed milk, season potatoes with salt, and transfer them to a warm serving bowl.