Preheat your oven to 350°F (175°C).

Cook the lasagna noodles according to package instructions until al dente, about 8–10 minutes. Drain and set aside.

In a large pot, heat olive oil over medium heat. Add chopped onion and minced garlic, cooking for about 3 minutes until translucent and fragrant.

Add chopped zucchini, diced bell pepper, spinach, and sliced mushrooms. Cook for 5–7 minutes until tender, seasoned with Italian seasoning, salt, and pepper.

In a bowl, mix ricotta cheese, shredded mozzarella, and grated Parmesan until smooth and creamy.

In a baking dish, spread a thin layer of béchamel sauce, layer noodles, half of the ricotta mixture, half of the sautéed vegetables, and a third of the béchamel. Repeat once more.

Top with remaining noodles, spread remaining béchamel, and sprinkle with remaining mozzarella and Parmesan cheese.

Cover with foil and bake for 30 minutes, then remove the foil and bake for an additional 15 minutes until golden brown.

Let the lasagna cool for 10 minutes before slicing. Garnish with fresh basil, if desired.