How to Make It
In a pot, cover the potatoes with water; bring to a boil. Add a generous pinch of salt and simmer over moderate heat until tender, 20 minutes. Drain.
Meanwhile, in a saucepan, combine the butter, cream and milk; bring to a simmer. Add the cheese and let stand for 1 minute; whisk until smooth.
Pass the warm potatoes through a ricer into the pot. Fold in the Parmesan cream. Season generously with salt and pepper and serve.