How to Make It
In a large pot, cover the turnips and potatoes with cold water and boil over high heat until the potatoes are tender and the turnips are almost tender, about 20 minutes. Drain well. Return the turnips and potatoes to the pot and shake over high heat to dry them out.
In a medium saucepan, warm the milk and cream over low heat; set aside. In a large bowl, mash the potatoes and turnips well but leave some lumps. Mix in the warmed milk and cream and the butter. Season with salt and pepper and serve hot.