Food & Cooking Recipes Main Dish Recipes Casserole Recipes Potato-Mushroom Pie 3.2 (214) 14 Reviews By Martha Stewart Martha Stewart Martha Stewart is a bestselling author, entrepreneur, and lifestyle expert who has taught millions of people through generations the joy of entertaining, cooking, gardening, collecting, crafting, and home renovating via her eponymous magazine, Martha Stewart Living, Emmy-winning television shows, and 99 books (and counting). Based in Katonah, N.Y., where she helms her 156-acre Bedford Farm, Martha is America's first self-made female billionaire. Editorial Guidelines Updated on June 12, 2017 Rate PRINT Share Close Photo: Gentl and Hyers Servings: 12 This gratin combines two comforting ingredients to their mutual advantage --and ours. Sliced potatoes encircle a casserole dish, with assorted wild mushrooms, such as chanterelle and oyster, taking spots alongside more potatoes. Fresh thyme gives the pie herbal undertones; Gruyere and Parmesan, melting in and around the layers during baking, make it soul-satisfying. Ingredients 2 tablespoons unsalted butter, plus more for dish 1 medium onion, cut into ½-inch dice 2 pounds assorted wild mushrooms, such as chanterelle, oyster, or black trumpet, coarsely chopped ¼ cup dry white wine, such as Sauvignon Blanc 1 ½ teaspoons coarse salt Freshly ground pepper 1 cup finely grated Gruyere cheese (about 4 ounces) 1 cup finely grated Parmesan cheese, about 3 ½ ounces 2 pounds Yukon Gold potatoes, peeled and cut into ⅛-inch-thick rounds 1 tablespoon finely chopped thyme leaves ¾ cup whole milk ½ cup heavy cream Directions Preheat oven to 350 degrees. Butter a 13-by-9-inch baking dish; set aside. Melt butter in a large skillet over medium heat. Add onion; cook, stirring occasionally, until softened, about 5 minutes. Add half of the mushrooms; cook until they are slightly softened. Add remaining mushrooms; cook, stirring occasionally, until mushrooms have released their juices and most of the liquid has evaporated, 8 to 10 minutes. Add wine; cook, stirring occasionally, until liquid has evaporated, 3 to 5 minutes. Remove from heat. Season with salt and pepper. Combine cheeses in a small bowl; set aside. Cover bottom of prepared dish with potato slices, slightly overlapping them. Sprinkle with half of the thyme and a pinch each of salt and pepper. Sprinkle with 1/3 of the cheese and half of the mushroom mixture. Repeat layering process, using all but 2 tablespoons cheese. Arrange remaining potato slices, slightly overlapping, around the edge of the dish. Stir together milk and cream in a bowl, and pour over top. At this point, dish can be refrigerated, covered, up to 1 day; let stand at room temperature 30 minutes before baking. Cover loosely with foil, and bake until bubbling, about 1 hour. Remove foil, and sprinkle with reserved cheese. Bake until top is golden, 20 to 30 minutes more. Transfer dish to a wire rack; let cool 10 minutes before serving. Cook's Notes Use a mandoline to make thin, even potato slices. Originally appeared: Martha Stewart Living, November 2006 Rate It PRINT