Food & Cooking Recipes Main Dish Recipes Casserole Recipes Turnip and Sweet Potato Gratin 3.5 (221) 4 Reviews By Martha Stewart Test Kitchen Martha Stewart Test Kitchen The recipes developed by our test kitchen team have undergone a rigorous process of development and testing, ensuring that every element is optimal, from ingredient amounts to method and cooking time. This process includes triple-testing recipes to ensure they meet our high standards. The many stellar cooks and food editors who have been part of our team include Sarah Carey, Lucinda Scala Quinn, Jennifer Aaronson, Shira Bocar, Anna Kovel, Greg Lofts, Riley Wofford, Lauren Tyrell, and Lindsay Leopold. Editorial Guidelines Updated on January 28, 2021 Print Rate It Share Share Tweet Pin Email Prep Time: 20 mins Total Time: 1 hrs 30 mins Servings: 8 This warming potato gratin, a great addition to the holiday table, is so simple that you'll want to make it all year long. Ingredients 1 ½ pounds turnips (about 3 medium), peeled and cut into ¼-inch-thick rounds Coarse salt and ground pepper ¼ cup all-purpose flour 1 pound sweet potatoes (about 2 medium), peeled and cut into ¼-inch-thick rounds 2 tablespoons unsalted butter, cut into pieces ¾ cup low-sodium chicken or vegetable broth ¼ cup dry white wine, such as Sauvignon Blanc 1 cup grated Gruyere cheese (4 ounces) Directions Preheat oven to 350 degrees. In an 8-inch square baking dish, arrange a single layer of turnips and sweet potatoes, overlapping slightly. Season with salt and pepper and sprinkle with one-third of the flour. Repeat to make 3 more layers, sprinkling with salt, pepper, and flour between layers. Dot top layer with butter, then slowly pour broth and wine into dish, keeping layers intact. Cover with foil and bake until vegetables are tender when pierced with a knife, 45 minutes. Increase oven temperature to 425 degrees. Remove foil and sprinkle cheese over dish. Bake until cheese is golden and bubbling, 12 to 15 minutes. Let gratin sit 10 minutes before serving. Rate it Print