A cheesy vegetarian lasagna that is even better the next day!
While the onions are cooking, wash and remove the stems from the mushroom and slice them.
Add garlic to onions and stir. Once the garlic becomes fragrant, add the mushrooms and cook for another 5-7 minutes. Increase the heat to medium-high and add the red wine. Let that cook down by half and then add the tomatoes (crushing the tomatoes with your hand as you add them to the pot) and stir. Bring to a strong simmer and then decrease the temperature to medium-low, stir. Simmer for 45 minutes to an hour.
Using a 9x13 baking dish, put enough sauce to cover the bottom of the dish with a thin layer. Add enough lasagna noodles to cover the sauce. Top with ½ of the container of parmesan (or less if you do not want to use as much), ½ of the container of ricotta and ¼ of the mozzarella package (I tore the pieces to more evenly distribute). Scatter half of the spinach over the top and then cover with ⅓ of the sauce. Cover with another layer of lasagna noodles.
Repeat process above through the spinach. Top with remainder of the lasagna noodles and then the remainder of the sauce. Finish with the remaining ½ package of the mozzarella and parmesan.
Place the baking dish on a large baking sheet and cover with aluminum foil.