Roasted Portobello And Prosciutto Lasagna

From Bon AppétitFilling
3 tablespoons plus 2 teaspoons olive oil
2 1/2 pounds (about 10) portobello mushrooms, stems trimmed
1 cup chopped prosciutto (about 6 ounces)
2/3 cup chopped shallots (about 2 large)
1 teaspoon chopped fresh rosemary
1 teaspoon chopped fresh thyme


Sauce
4 cups whole milk
1 14-ounce can low-salt chicken broth
1 bay leaf
1/2 cup (1 stick) butter
2/3 cup all purpose flour
2 cups (about 8 ounces) shredded Gruyère cheese
1/3 cup grated Parmesan cheese
1/8 teaspoon ground nutmeg


Lasagna
1 pound lasagna noodles
1/2 cup grated Parmesan cheese
2 tablespoons butter, cut into 1/2-inch pieces

For filling:

• Preheat oven to 400°F.
• 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.
• Cut mushrooms into 1/3-inch-thick slices.
• Meanwhile, heat remaining 2 teaspoons oil in medium nonstick skillet over medium heat.
• Add prosciutto; sauté until browned, about 3 minutes.
• Add shallots, rosemary, and thyme.
• Cook until shallots are tender, stirring frequently, about 5 minutes.
• (Mushrooms 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 saucepan 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 Gruyère, 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 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 over, and dot with butter.
• (Can be made 1 day ahead. Cover and refrigerate.)

Preheat oven to 350°F.
Bake lasagna until top is golden brown and sauce is bubbling, about 45 minutes (about 1 hour if refrigerated).
Let stand 20 to 30 minutes before serving.

Yield: 8 servings.