Velvety bechamel sauce makes this cheesy lasagna even more comforting, creamy and delicious. It's a great vegetarian recipe to make ahead of time, freeze and then heat up when you're ready to dig in.
For the bechamel sauce:1.
In medium saucepan, melt butter over medium-low heat. Add flour, whisking constantly. Cook, whisking occasionally, 2-3 minutes.2.
Continue whisking constantly, slowly add half of the hot cream and half of the hot milk to saucepan.3.
Pour the remaining hot milk into the saucepan, in small increments, whisking mixture constantly, until a smooth paste forms.4.
Whisk remaining cream into the mixture, then add nutmeg and salt. Cook mixture, stirring with a wooden spoon, making sure to scrape bottom and sides, until sauce is thick and creamy, about 15 minutes. If any lumps form, stir sauce rapidly with a whisk. Season with pepper, taste; remove from heat.
For the lasagna:1.
Bring a large pot of lightly salted water to a boil over high heat and cook the pasta until al dente, about 1 minute. Drain and shock in cold water.2.
Preheat the oven to 350°F. Spread a layer of both bechamel and tomato sauce into a lasagna baking dish and cover with pasta sheets, cutting the sheets to fit if necessary.3.
Spread 1/3 of the béchamel sauce, mushrooms, tomato sauce, mozzarella and Parmigiano-Reggiano over the pasta. Repeat three more times for a total of four layers.4.
Spread the remaining bechamel sauce over the top layer of the pasta and sprinkle the remaining cheese over the sauce.5.
Bake the lasagna for 45 minutes, or until the top is golden, at 350°F. Let the dish rest for at least 15 minutes before cutting the lasagna. Enjoy!