Food & Cooking Recipes Lunch Recipes Roasted Portobello Melts Be the first to rate & review! 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: Anna Williams Prep Time: 40 mins Total Time: 50 mins Yield: 4 Ingredients 4 medium portobello mushrooms, stems removed ¼ cup extra-virgin olive oil Coarse salt and freshly ground pepper 2 sprigs rosemary Parmesan Bechamel 4 slices rustic bread, toasted 1 cup grated Gruyere Directions Preheat oven to 425 degrees. Brush both sides of mushrooms with oil. Arrange, stem-side down, in a 9-by-13-inch baking dish; season with salt and pepper and top with rosemary. Roast, flipping once, until mushrooms are tender, about 25 minutes. Let cool; slice 1/4 inch thick on the bias. Heat broiler. Spread 2 tablespoons bechamel on each bread slice. Divide sliced mushrooms among slices, then top each with 1/4 cup Gruyere. Broil until cheese is melted, 1 to 2 minutes. Serve. Rate it Print