Saute onions and garlic in oil until tender. Add zucchini, mushrooms, tomatoes, tomato paste and tomato sauce, oregano, thyme, basil and pepper. Simmer 15-20 minutes. Beat eggs, add ricotta, half the Parmesan cheese, spinach. Sprinkle with salt and pepper. Cook noodles according to directions on package. Cover bottom of pan with noodles, spread 1/2 ricotta mixture, then 1/2 Mozzarella slices, 1/2 vegetable mixture. Repeat layers. Sprinkle remaining Parmesan cheese on top. Bake at 350 degrees for 45 minutes or until bubbly. You may refrigerate and bake for 1 hour.