Ingredients
4 1/2 pounds russet potatoes (about 7), peeled and cut into 1-inch pieces
Coarse salt and ground pepper
1 cup heavy cream
1 cup whole milk
1/2 cup (1 stick) unsalted butter
1/4 to 1/3 cup prepared horseradish
1/2 cup sour cream
Preparation
In a large pot, bring potatoes to a boil in salted water over high, then reduce to a rapid simmer and cook until potatoes are tender when pierced with a knife, about 15 minutes. Drain and return potatoes to pot. With a potato masher, mash until potatoes are fluffy and free of large lumps. (For a smoother texture, pass potatoes through a ricer or food mill into pot.)
Meanwhile, in a small saucepan, heat cream, milk, and butter over medium-low until butter melts. Slowly pour cream mixture into potatoes, stirring until combined. Whisk in horseradish to taste and sour cream, and season with salt and pepper.
