01 - Preheat oven to 425°F. Line two large baking sheets with parchment paper.
02 - Arrange zucchini, eggplant, bell peppers, and onion on baking sheets. Drizzle with olive oil, sprinkle with dried Italian herbs, salt, and pepper. Toss well to coat evenly.
03 - Roast vegetables for 20 to 25 minutes, turning halfway through, until tender and lightly caramelized. Remove from oven and reduce temperature to 375°F.
04 - In a mixing bowl, combine ricotta cheese, egg, and half of the grated Parmesan. Stir until well blended and set aside.
05 - Spread a thin layer of tomato sauce on the base of a 9x13-inch baking dish. Layer with lasagna noodles, half the roasted vegetables, half the ricotta mixture, one-third of the shredded mozzarella, and more sauce.
06 - Repeat layering with noodles, remaining roasted vegetables, remaining ricotta mixture, one-third of the mozzarella, and sauce.
07 - Top with a final noodle layer, the remaining tomato sauce, and sprinkle with remaining mozzarella and Parmesan cheese.
08 - Cover the dish with aluminum foil and bake for 25 minutes.
09 - Remove foil and continue baking for an additional 15 to 20 minutes until the cheese is golden and bubbling.
10 - Allow the dish to rest for 10 to 15 minutes before slicing. Garnish with fresh basil if desired.