Food & Cooking Recipes Main Dish Recipes Casserole Recipes Mushroom and Leek Gratin 4.4 (15) 2 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 May 16, 2017 Print Rate It Share Share Tweet Pin Email Photo: Romulo Yanes Servings: 8 Serve this hearty side dish with Pork Roast with Apples and Gremolata as part of your holiday dinner. Ingredients 4 tablespoons extra-virgin olive oil 2 pounds large portobello mushrooms (6 to 8), stemmed and sliced ½ inch thick 2 leeks (white and light-green parts only), cut into ¼-inch-thick half-moons and rinsed Coarse salt and ground pepper ¼ cup dry white wine, such as Chardonnay ¾ cup heavy cream 2 tablespoons fresh lemon juice 1 tablespoon fresh thyme leaves 1 ounce Parmesan, finely grated (¼ cup) Directions Preheat oven to 375 degrees. In a large skillet, heat 2 tablespoons oil over medium-high. Working in batches if necessary, add mushrooms and cook, tossing occasionally, until softened, 10 to 15 minutes. Transfer to a paper-towel-lined plate. Wipe out skillet, return to heat, and add 2 tablespoons oil. Add leeks and season with salt and pepper. Cook, stirring frequently, until softened, 8 minutes. Add wine, and cook until almost evaporated, 2 to 3 minutes. Stir in cream, lemon juice, and thyme leaves. Transfer leek mixture to a 2-quart baking dish. Top with mushroom slices, overlapping slightly. Sprinkle with Parmesan and bake until edges are bubbling, 20 to 25 minutes. Serve warm. Rate it Print