Preheat your oven to 350°F (175°C).

In a large pot, boil water and cook the lasagna noodles according to package instructions until al dente, about 8-10 minutes. Drain and rinse under cold water.

In a large skillet, heat 2 tablespoons of olive oil over medium heat. Add diced onion and minced garlic, and sauté for about 3 minutes until soft.

Stir in chopped zucchini, bell pepper, spinach, and sliced mushrooms. Add Italian seasoning, salt, and pepper. Cook for about 5-7 minutes until vegetables are tender.

In a separate bowl, combine ricotta cheese, shredded mozzarella, and grated Parmesan cheese. Mix well until creamy.

In a 9x13-inch baking dish, layer with béchamel sauce, then three noodles, half of the ricotta mixture, half of the veggies, and a third of the béchamel sauce. Repeat until all ingredients are used, finishing with noodles.

Pour remaining béchamel sauce over the top and sprinkle with the last of the shredded mozzarella and Parmesan cheese.

Cover with foil and bake for 30 minutes. Remove foil and bake for an additional 15 minutes until bubbly and golden brown.

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