Cook the Mushrooms and Tomatoes

1. Saute chopped onions and cook until they become translucent.Add the sliced mushrooms to the skillet and cook for about 8-10 min.

2. Afterward, season with dried thyme, dried oregano, salt, and pepper. If using, pour in the white wine and cook until it evaporates, about 2–3 minutes.

3. Then, add the halved grape tomatoes and cook for an additional 2–3 minutes.

Making the Bechamel Sauce

1. In a medium saucepan, melt the butter over medium heat. Add the flour and whisk continuously until the mixture turns a light golden color, about 2–3 minutes.
2. Gradually add the warmed milk, whisking constantly to avoid lumps. Season with a pinch of nutmeg, salt, and pepper.

Assembling the Lasagna

1. Preheat your oven to 375°F (190°C)
2. Cook the lasagna noodles according to the package instructions until al dente.
3. Spread a thin layer of Bechamel sauce on the bottom of a 9×13 inch (23×33 cm) baking dish. Place a layer of lasagna noodles over the sauce.
4. Then, spread half of the mushroom and tomato mixture over the noodles.

5. Sprinkle half of the chopped spinach over the mushrooms and tomatoes.

6. Pour about one-third of the Bechamel sauce over the spinach. Sprinkle with one-third of the mozzarella and Parmesan cheeses.

7. Repeat the layers: noodles, mushroom and tomato mixture, spinach, Bechamel, cheeses.

Baking the Lasagna

1. Cover the baking dish with aluminum foil.
2. Bake in the preheated oven for 25 minutes.
3. Remove the foil and bake for an additional 20 minutes, or until the top turns golden and bubbly.