Food & Cooking Recipes Main Dish Recipes Casserole Recipes Apple, Leek, and Butternut Squash Gratin 3.6 (173) 8 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 June 12, 2017 Print Rate It Share Share Tweet Pin Email Photo: Dana Gallagher Prep Time: 30 mins Total Time: 1 hrs 20 mins Servings: 4 This gratin is a savory and sweet side dish for chicken or pork. Ingredients 3 tablespoons extra-virgin olive oil 2 medium leeks, white part only, trimmed of roots and tough outer leaves, thinly sliced crosswise, well washed and dried Coarse salt and ground pepper ½ cup dry sherry 1 tablespoon chopped fresh sage, plus leaves for garnish 1 pound butternut squash, peeled, seeded, and sliced ⅛-inch thick 1 pound apples, such as Gala, Cortland, Baldwin, or Macoun, peeled, halved, cored, and cut into ⅛-inch thick slices ½ cup freshly grated Parmesan cheese Directions Preheat the oven to 350 degrees. In a 10-inch skillet, heat 2 tablespoons of oil over medium heat. Add leeks and 2 tablespoons water; season with salt and pepper. Cook, stirring occasionally, until they begin to brown, about 10 minutes. Add sherry and sage and cook until liquid is reduced to a glaze, about 3 minutes; set aside. In a 2-quart shallow baking dish, arrange squash in overlapping layers; season with salt and pepper. Spread leeks evenly over the squash. Arrange apples in an overlapping layer over the leeks. Brush apples with remaining tablespoon oil. Cover tightly with aluminum foil. Bake 45 minutes. Uncover and sprinkle cheese over the top. Raise the oven temperature to 450 degrees and bake 10 minutes, or until the cheese has melted and is golden brown. The tip of a paring knife should easily pierce the gratin. Let cool 10 minutes before serving. Garnish with sage leaves. Cook's Notes To cook gratin in advance, prepare through step 2, cover, and refrigerate for up to 24 hours Rate it Print