01 -
Heat your oven to 375°F (190°C). Lightly oil a 9x13-inch baking dish.
02 -
Boil the lasagna sheets in a big pot of salted water until they're just tender. Drain them and keep aside.
03 -
In a large pan, heat olive oil and sauté the onion for 3-4 minutes. Stir in garlic, then add mushrooms and dried thyme. Cook until the mushrooms soften. Finally, throw in the spinach and cook until it wilts completely.
04 -
Spread marinara sauce to start, then layer pasta sheets, ricotta, spinach and mushroom mixture, followed by shredded cheeses. Keep layering like that and finish with marinara and cheese on top.
05 -
Cover with foil and bake for 25 minutes. Remove the foil and bake another 10-15 minutes until the cheese gets golden. Let it rest for a few minutes, then serve with some fresh basil.