Preheat oven to 350 degrees F (175 degrees C). Lightly brush a medium baking dish with oil.
Add the oil to a skillet over medium heat. Mix the onion, red bell pepper, carrots, garlic and pine nuts and sauté for 5 minutes.
Add the tomato sauce into the skillet. Season with oregano, basil, salt, pepper and chili flakes. Bring the mixture to a boil, reduce heat to low, and simmer 10 minutes, until vegetables are tender.
In the bottom of the prepared baking dish, layer the zucchini strips. In a bowl, beat together the ricotta cheese and egg, and spread over the zucchini. Scoop 1/2 veggie mixture over the ricotta cheese and egg mixture, and sprinkle with 1/2 the mozzarella cheese. Layer with the eggplant, veggie mixture, and mozzarella. Top with Parmesan cheese.
Bake 45 minutes in the preheated oven. Allow to sit 10 minutes before slicing to serve.
