Sausage and Mushroom Lasagna with Béchamel

Preheat your oven to the optimal temperature of 375 degrees Fahrenheit (or 190 degrees Celsius).

To ensure a smooth process, lightly coat the bottom of a 9x13-inch baking dish with cooking spray.

Next, cook sliced sausage in a skillet over medium heat until it reaches a browned and crumbly state, approximately 10 minutes. Remove the cooked sausage from the skillet with a slotted spoon and set it aside.

To prepare the béchamel sauce, melt butter in a saucepan over medium heat and whisk in flour. Continue cooking until the mixture becomes light and frothy, about 2 minutes, while constantly whisking; gradually whisk in milk. Whisk in salt and nutmeg to add depth to the sauce. Bring the sauce to a gentle simmer, whisking constantly until it thickens, approximately 10 minutes. Remove the sauce from heat and set it aside.

In a separate bowl, beat an egg until well combined; stir in ricotta cheese and chopped parsley until the mixture is smooth and even. Set this mixture aside.

To assemble your lasagna, pour approximately 1 1/2 cups of marinara sauce into the prepared baking dish. Add a layer of lasagna noodles, overlapping them if necessary.

Now, create the first layer by topping the sauce with 4 lasagna noodles. Layer 1/3 of the ricotta mixture, followed by 1/3 of the cooked sausage, 1/3 cup of sliced mushrooms, 1/4 of the béchamel sauce, 1 cup of shredded mozzarella cheese, 1/8 cup of grated Parmesan cheese, and a final layer of marinara sauce over the noodles. Repeat this process two more times, ending with a final layer of noodles topped with remaining marinara sauce, béchamel sauce, mozzarella cheese, and Parmesan cheese. Cover the dish with aluminum foil.

Place your lasagna in the preheated oven and bake until it is bubbly and the noodles are tender, approximately 1 hour. Remove the foil and continue baking until the top cheese layer is golden brown, about an additional 5 minutes. Allow your lasagna to rest for 10 minutes before cutting it into individual portions.