Preheat your oven to 350°F (175°C).

Cook the lasagna noodles according to the package instructions (8-10 minutes). Drain and rinse under cold water.

In a large pot, heat olive oil and sauté onion and garlic until translucent (3-5 minutes). Add zucchini, bell pepper, spinach, and mushrooms, and cook until tender (5-7 minutes).

In a bowl, combine ricotta cheese, mozzarella, and Parmesan until smooth.

In a baking dish, start layering: béchamel, noodles, half of ricotta mixture, half of vegetables, and another layer of béchamel. Repeat and finish with noodles and béchamel.

Cover with foil and bake for 30 minutes. Remove foil, add remaining cheeses, and bake uncovered for an additional 15 minutes.

Let the lasagna cool for about 10 minutes before serving. Garnish with basil.