Everybody thinks of making mashed potatoes with milk, cream, half-and-half, or sour cream, but only in the South will you find them whipped with tangy buttermilk, just as they were when folks still churned their own butter. Horseradish is a much more modern innovation—and, in my opinion, a great one. I’d just as soon not eat mashed potatoes if they’re not served immediately after being beaten. Reheating them in a double boiler or wrapped in foil in the oven may keep them hot, but they’re still almost guaranteed to be lumpy.
Place the potatoes in a large saucepan with enough water to cover, and bring to a boil. Reduce the heat to moderate, cover, cook till the potatoes are very tender, 20 to 25 minutes, and drain.
Transfer the potatoes to a large, heavy saucepan over low heat, add the butter, and beat with an electric mixer till the potatoes are mashed and the butter well incorporated. Add the remaining ingredients and continue beating over low heat till the potatoes are light and fluffy and not at all lumpy. Serve piping hot.
© 2007 All rights reserved. Published by Houghton Mifflin Harcourt.