Preheat your oven to 200°C (390°F). Slice the zucchini into thin, even rounds and spread them on a baking sheet. Roast for about 15 minutes until slightly golden and fragrant, then set aside to cool.
While the zucchini roasts, wilt the fresh spinach in a dry skillet over medium heat for 2-3 minutes until dark green and tender. Squeeze out excess moisture, then chop roughly and set aside.
Prepare your tomato sauce by heating olive oil in a saucepan over medium heat. Add the minced garlic and sauté until fragrant, about 30 seconds. Pour in crushed tomatoes, add oregano, salt, and pepper, then simmer for 15 minutes until thickened and aromatic.
In a mixing bowl, combine ricotta cheese, beaten egg, grated Parmesan, salt, and pepper. Mix until smooth and creamy.
Roast the red bell peppers until smoky and tender, then peel and slice them into strips. Set aside.
Begin assembling the lasagna by spreading a thin layer of tomato sauce in the bottom of your dish. Place a layer of noodles over the sauce, slightly overlapping them.
Spread a third of the ricotta mixture over the noodles, then layer roasted zucchini, wilted spinach, and roasted bell peppers on top. Repeat the layers until all ingredients are used, ending with a final layer of noodles topped with sauce and shredded mozzarella.
Cover the assembled lasagna with aluminum foil and bake for 35 minutes. Remove the foil and bake an additional 10 minutes until the top is bubbly and golden brown.
Let the lasagna rest uncovered for at least 10 minutes before slicing. This helps the layers set and makes serving easier.
Slice carefully with a sharp knife, serving warm with a sprinkle of fresh basil or extra Parmesan if desired. Enjoy the vibrant colors and rich, cheesy layers in every bite!
