Preheat the oven to 425 degrees F.
Place the potatoes on a roasting pan and roast until tender, 45 minutes to 1 hour. Remove from the oven and let sit until cool enough to handle. Peel the potatoes and place in a large mixing bowl. Add the remaining ingredients and mash with a potato masher or heavy fork. Cover to keep warm until ready to serve.
Yield: 4 servings