Preheat your oven to 375°F (190°C). Cook the lasagna noodles according to the package instructions, ensuring they are al dente. Drain and set aside.

In a large skillet, heat some olive oil over medium heat. Add the sliced mushrooms and sauté until they become soft. Stir in the fresh spinach and cook until wilted, about 2-3 minutes. Remove from heat.

In a large mixing bowl, combine the shredded chicken, sautéed mushrooms and spinach, ricotta cheese, and half of the Alfredo sauce. Season with salt, pepper, and Italian seasoning if desired. Mix until well combined.

Spread a thin layer of Alfredo sauce on the bottom of a baking dish. Start with three lasagna noodles as the first layer, then add half of the chicken mixture, followed by a layer of mozzarella cheese, and another layer of Alfredo sauce.

Repeat the layering process with another three lasagna noodles, the remaining chicken mixture, more mozzarella, and another layer of Alfredo sauce. End with the last three noodles on top, covering them with the remaining Alfredo sauce and sprinkling the rest of the mozzarella and Parmesan cheese.

Cover the baking dish with foil and bake in the preheated oven for 25 minutes. Remove the foil and continue to bake for an additional 15-20 minutes, until the cheese is bubbly and golden.

Once baked, remove the lasagna from the oven and allow it to cool for a few minutes before slicing and serving.