Cheesy Chicken and Mushroom Lasagne - cremini mushrooms

Method

• Preheat oven to 425 with rack in middle.
• Cook mushrooms, garlic, 1/4 teaspoons salt, and 1/8 tsp pepper in olive oil and 1 tablespoon butter in a 4 quart heavy saucepan over medium heat, stirring occasionally, until mushrooms are softened, about 3 minutes.
• Add the wine and simmer briskly for 2 minutes.
• Transfer mushroom mixture to a large bowl and stir in chicken.
• Set aside saucepan.
• Bring milk to a bare simmer in a medium saucepan.
• Melt remaining 4 tablespoons butter in 4 quart saucepan over medium-low heat.
• Add flour and cook roux, stirring constantly, 3 minutes.
• Add hot milk in a slow stream, whisking constantly.
• Add thyme, 3/4 tsp salt, and 1/2 tsp pepper and simmer, whisking constantlhy, until thickened, 5-6 minutes.
• Remove from heat and reserve 1 cup of sauce.
• Stir parmesan into the sauce remaining in the pan, then stir in mushroom filling.
• Pour half of reserved plain sauce into 8"square baking dish, spreading evenly to coat bottom.
• Add three lasagna noodles, overlapping slightly, and 1/3 of mushroom filling, spreading evenly, then sprinkle 1/4 of Gruyere over the top.
• Repeat 2 times.
• Top with remaining 3 lasagna noodles and remaining plain sauce, spreading evenly.
• Sprinkle with remaining Gruyere.
• Cover with foil, tenting slightly to prevent foil from touching top of lasagne, but sealing all the way around edges, and bake for 30 minutes.
• Remove foil and bake until cheese is golden, about 15 minutes.
• Let lasagne stand 10minutes before serving.