Bring a large pot of lightly salted water to a boil and cook the lasagna noodles for 10 to 12 minutes. Drain the noodles and drizzle them with 1 tablespoon of the olive oil, and then set the noodles aside for later use. (If you are using no-boil noodles, skip this step.)
Heat the remaining 2 tablespoons olive oil in a large skillet set over medium heat and cook the shallots until softened and translucent, 4 to 5 minutes. Add in the garlic and zucchini, and cook for 1 minute. Stir in the spinach and cook until wilted, 2 to 4 minutes.
In a large bowl, stir to combine the ricotta, Parmesan, salt, pepper and egg, and set aside for a later use.
To assemble the lasagna, spoon 1/2 cup of the Chunky Marinara Sauce into the bottom of a 9-by-13-inch baking dish. Top with 5 noodles, slightly overlapping. Spread one-third of the ricotta mixture over the noodles, then add one-third of the cooked zucchini and spinach, evenly distributing over the ricotta. Top with 2 cups of the mozzarella, then top with 1 cup of the sauce. Repeat the layering two more times, ending with a layer of noodles and a sprinkle of mozzarella.
Cover with foil and bake for 40 minutes.
Remove the foil and continue to bake until bubbling and cooked through, 10 to 20 minutes more. Cool for 10 to 15 minutes before serving.
Chunky Marinara Sauce:
Heat the olive oil in a large saucepan set over medium heat and add the carrots, celery and onions, and cook until soft and translucent, stirring occasionally, 8 to 10 minutes.
Stir in the garlic and cook for 1 minute, then stir in the oregano, chile flakes, tomato puree, chopped tomatoes and their juices, basil leaves and some salt and pepper. Bring to a simmer and cook until the sauce has thickened, about 30 minutes.
This recipe has been updated and may differ from what was originally published or broadcast.