¾ cup extra-virgin olive oil, divided
4 large shallots, minced
2 lbs. wild mushrooms (oyster, shiitake, cremini, baby bellas), sliced
1 cup dry white wine
4 Tbsp. butter or herb oil
3 large garlic cloves, minced
4 Tbsp. flour
3 cups half-and-half
1 cup grated fontina, divided
1 cup grated Gruyere, divided
½ tsp. freshly grated nutmeg
Kosher salt and freshly ground black pepper, to taste
1 8-oz. ball fresh mozzarella, grated
2 9-oz. boxes no-boil lasagna sheets
1 cup freshly grated Parmesan
• Preheat the oven to 350 degrees.
• In a large pan over medium-high heat, warm ¼ cup olive oil. When the oil begins to shimmer, add half the shallots and saute, stirring occasionally, until translucent, about 5 minutes. Add the mushrooms and toss to coat. Cook until the mushrooms begin to color but are still plump, 12 to 15 minutes. Add the white wine to deglaze the pan and continue to cook until the mixture is syrupy, 5 to 7 minutes. Place the mushrooms in a large bowl and set aside.
• Make a bechamel by melting the butter in a saucepan over medium heat. When the butter foams, add the remaining shallots and cook until they begin to turn translucent, about 5 minutes. Add the garlic and stir to combine. Cook until the garlic has started to soften, then sprinkle in the flour and stir to combine. Cook until the mixture turns light brown and smells nutty, 5 to 7 minutes. Slowly add the half-and-half, whisking constantly. Cook until the sauce is thick and creamy, 3 to 5 minutes.
• Add ¼ cup fontina, ¼ cup Gruyere, the nutmeg, salt and pepper and stir to combine. Reserve 1 cup bechamel, and pour the rest over the mushrooms. Stir to combine.
• Assemble the lasagna by spreading the reserved bechamel in the bottom of a 9-by-13-inch baking pan. Place a layer of lasagna sheets over the sauce, being careful not to overlap. Layer about one-third of the mushroom mixture over the pasta, and sprinkle with one-third of the fontina and Gruyere. Add another layer of pasta, and top with about one-third of the mozzarella. Repeat until the pan is full.
• Top with remaining cheeses and the Parmesan. Cover with a buttered sheet of aluminum foil and refrigerate up to 2 days (and remove 30 minutes before baking) or bake immediately 45 minutes. Remove foil and continue baking until golden and bubbling.