- 8 russet potatoes, peeled and quartered
- 10 tablespoons unsalted butter, at room temperature
- 1 cup heavy cream
- 1/2 cup whole milk
- 2 1/2 teaspoons kosher salt
- 1/4 teaspoon black pepper
- Heat oven to 300° F.
- Place the potatoes in a large pot with enough cold water to cover them by 2 inches. Bring to a boil and cook until tender, about 15 minutes. Drain well, return to pot, and mash. Add 8 tablespoons of the butter, the cream, milk, salt, and pepper.
- Transfer to a casserole and dot with the remaining butter, cut into small pieces. Place in oven, uncovered, to keep warm for up to 1 hour.