My friend Kayla called these "mashed poturnips" when I first made them, and the name has stuck. Turnips cooked down with milk, butter, and fresh thyme, and then whipped into mashed potatoes and sprinkled with Parmigiano-Reggiano. Makes a wonderfully silky steak side. First published on my food blog My Weekend's Cooked: http://myweekendscooked.blogspot.com/2014/02/creamy-mashed-potatoes-with-turnip-puree.html —Lucie Monk
Yukon Gold potatoes, peeled and chopped into 1-inch cubes
turnips, peeled and chopped into 1/2-inch cubes
In a medium saucepan, combine turnip, butter, milk, and thyme over medium-high heat. Bring to a boil over and then simmer, partially covered, for twenty-five minutes.
Remove thyme. Using an immersion blender (or a food processor), purée the mixture. Return mixture to pan (if using a food processor), and keep warm.
Meanwhile, place potatoes in a large, heavy-bottomed pot, covered by at least 1 inch of salted water. Bring to a rolling boil, then simmer until potatoes can be pierced cleanly by a fork (10–15 minutes.) Drain in a colander, then mash completely in a bowl.
Add mashed potatoes into the saucepan with the turnip purée. Raise heat to medium and, stirring, warm potatoes completely through.
Lower heat to medium-low. Add grated cheese; stir until melted. Season with salt and pepper and serve.