1
Preheat oven to 375°F (190°C).
2
Heat olive oil in a skillet and sauté zucchini, bell pepper, and mushrooms until soft, about 5–7 minutes. Add spinach and cook until wilted. Season with salt, pepper, and Italian seasoning.
3
Spread a thin layer of tomato sauce in the bottom of a baking dish. Layer 3 lasagne sheets, half the vegetables, half the ricotta, and a layer of sauce. Repeat.
4
Top with remaining pasta sheets, the rest of the sauce, mozzarella, and Parmesan cheese.
5
Cover with foil and bake for 30 minutes. Remove foil and bake for another 10–15 minutes until bubbly and golden.
6
Let rest 10 minutes before slicing and serving.
