How to Make It
In a large pot of boiling salted water, cook the potatoes over moderate heat until tender, about 25 minutes. Drain well. Return the potatoes to the pot and cook over high heat for 1 minute to dry them out slightly. Pass the potatoes through a ricer and return them to the pot.
In a small saucepan, cook the butter over moderate heat until the milk solids turn dark golden, about 4 minutes. Add all but 2 tablespoons of the brown butter to the potatoes along with the milk and crème fraîche and stir well. Season with salt and stir over moderate heat until hot. Drizzle the remaining brown butter over the potatoes and serve.