6 tablespoons unsalted butter, divided
1 pound baby bella mushrooms, trimmed and sliced
1 small onion, diced
2 - 3 large cloves garlic, minced
1/2 cup dry white wine
3 cups cooked and shredded chicken (equivalent of 1 rotisserie chicken)
1/2 cup plus 2 tablespoons all-purpose flour
4 cups warmed milk, preferably whole milk
1 cup chicken stock
2 teaspoons kosher salt, plus more to taste
1/4 teaspoon dry mustard powder, plus more to taste
1 teaspoon dry sherry or marsala (optional)
Freshly ground black pepper
1 cup grated Parmesan, divided
16 lasagna noodles (from a 1 pound box)
2 cups shredded mozzarella cheese
2 cups grated gruyere cheese
Preheat the oven to 350°F. Lightly grease a large, rectangular casserole dish or lasagna pan. Bring a large pot of heavily salted water to a boil.
In a large Dutch oven or heavy pot, melt 2 tablespoons of butter on medium-high heat. Add the mushrooms and sauté until they start sweating liquid, about 4 minutes. Add the onion, garlic, and a pinch of salt. Continue cooking, stirring often, until onions are translucent, about 8 minutes. Add the wine and bring to a boil; continue cooking until most of the liquid has evaporated out. Transfer the mushroom mixture to a separate bowl along with the shredded chicken.
To make the bechamel (white sauce), add the remaining 4 tablespoons of butter to the pot and melt over medium heat. Stir in the flour until thick paste forms; continue cooking to remove the "raw" taste, about 1 minute. Pour in the milk and chicken stock and cook, whisking often until the mixture is thickened, 10 to 15 minutes. Whisk in the salt, mustard powder, sherry, and a generous amount of freshly ground black pepper, followed by 1/4 cup grated Parmesan.
While the bechamel is thickening, prepare the noodles. Add the noodles to the boiling water and cook, stirring occasionally, until al dente, 7 to 8 minutes. Drain and arrange on a lightly greased sheet pan to prevent sticking.
Fold the chicken and mushroom mixture into the bechamel. Taste and adjust seasoning. (Be liberal with salt and pepper.) In a separate bowl, combine mozzarella, gruyere, remaining 3/4 cup Parmesan cheese. Spread 1 cup of the chicken mixture into the bottom of the prepared baking dish. Arrange 4 noodles on top of the chicken, overlapping if necessary. Spread about 1 cup of chicken mixture over the noodles followed by 1 cup of cheese. Repeat layers, ending with the remaining cheese on top.
Bake, uncovered, until the lasagna is hot and bubbly, about 45 minutes. Allow to cool for 10 to 15 minutes before serving.
The lasagna can be assembled and refrigerated up to 24 hours in advance; just add 15 minutes to the cooking time when ready to bake. It can also be frozen for up to three months; wrap the lasagna pan in foil and freeze until solid. To cook, bake the frozen lasagna, covered, for 1 hour and 15 minutes, and then uncover and bake another 30 to 45 minutes until cooked through.
Serves 8 to 10.
Uploaded: Mar 12, 2014