01 - Preheat oven to 425°F. Line two large baking sheets with parchment paper. Arrange zucchini, eggplant, bell peppers, and onion across the sheets. Drizzle with olive oil, sprinkle with dried Italian herbs, salt, and pepper, then toss to coat evenly.
02 - Roast vegetables for 20 to 25 minutes, flipping halfway through, until tender and lightly caramelized. Remove from oven and reduce oven temperature to 375°F.
03 - In a mixing bowl, combine ricotta cheese, egg, and half of the grated Parmesan cheese. Stir thoroughly and set aside.
04 - Spread a thin layer of tomato sauce in a 9x13-inch baking dish. Arrange a layer of lasagna noodles, half the roasted vegetables, half the ricotta mixture, one-third of the mozzarella cheese, then more tomato sauce.
05 - Add another layer of noodles followed by remaining roasted vegetables, remaining ricotta mixture, one-third of the mozzarella, and additional tomato sauce.
06 - Finish with a final layer of noodles and remaining tomato sauce. Sprinkle the remaining mozzarella and Parmesan cheese evenly over the top.
07 - Cover the dish with aluminum foil and bake for 25 minutes at 375°F.
08 - Remove foil and continue baking for 15 to 20 minutes until the cheese is golden and bubbling.
09 - Let the lasagna rest for 10 to 15 minutes before slicing. Garnish with fresh basil if desired.