Preparation

• Put the potatoes in an 8-qt. stockpot. Add the salt and enough water to cover the potatoes by about 2 inches. Cover and bring to a boil over medium-high heat. Reduce the heat to medium low and simmer, uncovered, until the potatoes are tender but not falling apart, 15 to 20 minutes.
• Meanwhile, heat the heavy cream (or half-and-half or milk) in the microwave or in a medium saucepan over medium heat until hot but not boiling. Keep hot.
• Drain the potatoes and return them to the pot over low heat. Add the butter, about two-thirds of the hot cream, and the white pepper. With a potato masher, mash the potatoes to your desired consistency, adding the remaining cream if they seem dry. Season with more salt and white pepper to taste.
• To keep them warm, transfer the mashed potatoes to a heatproof bowl, cover them tightly with foil, and set the bowl over a saucepan of barely simmering water.