Preheat the oven to 375°F (190°C).
In a medium saucepan over medium heat, heat the olive oil. Add the diced onion and minced garlic, sautéing for about 3-4 minutes or until the onion becomes translucent.
Incorporate the zucchini, bell peppers, and mushrooms. Cook for an additional 5-7 minutes and then stir in the fresh spinach until wilted. Remove from heat and allow to cool slightly.
In a large mixing bowl, combine the ricotta cheese, 1 cup of shredded mozzarella cheese, grated Parmesan cheese, chopped basil, dried oregano, salt, and black pepper.
Spread a thin layer of alfredo sauce on the bottom of the baking dish. Place 3 lasagna noodles on top.
Spoon half of the ricotta mixture over the noodles, followed by half of the sautéed veggie mixture. Drizzle about ⅓ of the alfredo sauce over the vegetables.
Repeat the layering process: another 3 noodles, the remaining ricotta mixture, the rest of the veggie mix, and another ⅓ of the alfredo sauce.
Top with the last 3 noodles and the remaining alfredo sauce. Sprinkle the remaining 1 cup of mozzarella cheese on top.
Cover the baking dish with aluminum foil (to prevent sticking, use a piece of parchment paper between the foil and the cheese).
Bake in the preheated oven for 25 minutes. Remove the foil and bake for an additional 15-20 minutes until the cheese is bubbly and golden brown.
Allow to cool for 10 minutes before slicing and serving.