PORTOBELLO PROSCIUTTO LASAGNA

Steps:

• For Filling - Preheat oven to 400F
• Brush rimmed baking sheet with 1 Tablespoon olive oil.
• Toss mushrooms with 2 Tablespoons olive oil in large bowl to coat
• Arrange mushrooms, gill side up, in single layer on prepared baking sheet
• Sprinkle with salt and pepper
• Roast until tender, about 45 minutes
• Cool mushrooms
• Cut mushrooms into 1/3 inch thick slices
• Meanwhile, heat remaining 2 teaspoons oil in medium nonstick skillet over medium heat
• Add prosciutto; saute until browned, about 3 minutes
• Add shallots, rosemary & thyme
• Cook until shallots are tender, stirring frequently, about 5 minutes (Mushroom and prosciutto-shallot mixture can be made 1 day ahead. Cover separately and chill)
• For Sauce - Bring milk, broth and bay leaf to simmer in heavy large suacepan over medium heat
• Remove from heat
• Let stand 10 minutes; discard bay leaf
• Melt butter in heavy medium saucepan over medium-low heat
• Whisk in flour; stir 2 minutes
• Whisk in hot milk mixture; bring to boil, whisking frequently
• Reduce heat to low; simmer 5 minutes, stirring frequently
• Remove from heat; stir in Gruyere, Parmesan and nutmeg
• Season to taste with salt and pepper
• For Lasagna - cook noodles in large pot of boiling salted water until almost tender but slightly undercooked (noodles will finish cooking in oven)
• Drain and rinse with cold water
• Drain again; pat dry
• Butter 13x9x2-inch glass baking dish
• Spread 1 cup of sauce over bottom of prepared dish
• Arrange 1/3 of noodles over sauce, overlapping to fit
• Spread about 1 2/3 cups sauce over noodles
• Arrange 1/2 of mushrooms over sauce
• Scatter 1/2 of prosciutto mixture over mushrooms
• Arrange 1/2 of remaining noodles over mushrooms, overlapping to fit
• Spread 1 2/3 cups sauce over noodles
• Arrange remaining mushrooms over sauce, sprinkle with remaining prosciutto and top with remaining noodles
• Spread remaining sauce over noodles, sprinkle Parmesan cheese and dot with butter. (Can be made to this point 1 day ahead. Cover and refrigerate)
• Preheat oven to 350F
• Bake lasagna until top is golden brown and sauce is bubbling, about 45 minutes (about 1 hour if refrigerated)
• Let stand 20 - 30 minutes before serving