Lasagna with Roasted Portobello Mushrooms
MUSHROOMS
- 10 medium (about 2½ pounds) portobello mushrooms
- 2 tablespoons plus 2 teaspoons extra virgin olive oil
- Salt and freshly ground black pepper to taste
- 4 ounces prosciutto, cut into ¼-inch dice (about 1 cup)
- 2/3 cup chopped shallots
- 1 teaspoon chopped fresh rosemary
- 1 teaspoon chopped fresh thyme
- 3½ cups milk
- 2 cups Homemade White Chicken Stock or canned
- reduced-sodium chicken broth
- 1 bay leaf
- ½ cup (1 stick) unsalted butter
- 2/3 cup all-purpose flour
- 2 cups (8 ounces) shredded Gruyère cheese
- 1/3 cup freshly grated Parmesan cheese
- 1/8 teaspoon freshly grated nutmeg
- Salt and freshly ground black pepper to taste
- 15 lasagna noodles
- ½ cup (2 ounces) freshly grated Parmesan cheese
- 2 tablespoons unsalted butter, cut into pieces
Instructions:
This luxurious lasagna has become a staple at my holiday parties because with a few minor adjustments, it can serve as a vegetarian main course.
- To prepare the mushrooms, preheat the oven to 400°F. Trim the dirty ends from the mushroom stems, but leave the stems attached to the caps. Rinse the mushrooms well under cold water to remove any grit. Toss the mushrooms with 2 tablespoons of the oil in a large bowl. Arrange on a large oiled baking sheet. Season with salt and pepper. Roast until tender, about 45 minutes. Remove from the oven and cool completely. Cut the mushrooms lengthwise into 1/3-inch-thick slices, including the stems.
- Heat the remaining 2 teaspoons of the oil in a medium nonstick skillet over medium heat. Add the proscuitto and cook, stirring often, until browned, about 5 minutes. Add the shallots, rosemary, and thyme. Cook,
- stirring often, until the shallots are tender, about 4 minutes. Remove from the heat and set aside. (The mushrooms and prosciutto can be prepared up to 1 day ahead, cooled, separately covered, and refrigerated.)
- To make the sauce, bring the milk, stock, and bay leaf to simmer in a large saucepan or in a microwave. Let stand 10 minutes; discard the bay leaf.
- Melt the butter in a medium, heavy-bottomed saucepan over medium-low heat. Whisk in the flour and let it bubble without browning, for 2 minutes. Whisk in the hot milk mixture, and bring to a simmer over high heat, whisking often. Reduce the heat to low and simmer until slightly thickened, about 5 minutes. Remove from the heat and stir in the Gruyère, Parmesan, and nutmeg. Season with salt and pepper. (The sauce can be made 1 day ahead. Transfer to a bowl and press a piece of plastic wrap directly on the surface of the sauce. Pierce a few slits in the wrap to allow steam to escape. Cool until tepid, then refrigerate. Reheat in a saucepan over low heat before using.)
- Position a rack in the center of the oven and preheat to 350°F. Lightly butter a 13 × 9-inch glass baking dish.
- Bring a large pot of lightly salted water to a boil over high heat. Add the lasagna noodles, one at a time, and cook until barely tender (they will continue to cook in the oven), about 7 minutes. Drain and rinse under cold running water. Pat the noodles dry on clean kitchen towels.
- Spread 1 cup of the warm sauce in the baking dish. Arrange 4 slightly overlapping noodles lengthwise in the dish, then 1 noodle trimmed to fit crosswise. Spread with a third of the sauce. Arrange half of the mushrooms on top, then scatter with half of the prosciutto mixture. Layer with 5 more noodles, half of the remaining sauce, and the remaining mushrooms and prosciutto mixture. Finish with the remaining noodles and spread with the remaining sauce. Sprinkle the Parmesan evenly over top, and dot with the butter. (The lasagna can be made 8 hours ahead, cooled, covered, and refrigerated.)
- Bake until the top is golden brown and the sauce is bubbling, about 45 minutes (or 1 hour if refrigerated). Let stand 10 minutes. Cut into portions and serve.