Replacing the lasagna noodles with eggplant slices keeps this lasagna recipe healthy and gluten-free. Slideshow: More Lasagna Recipes
Preheat the oven to 425°. In a large frying pan, heat the extra-virgin olive oil over medium high heat. Add the onion and cook for 5 minutes, until it’s soft and beginning to brown. Add the garlic and cook for 30 seconds. Add the broccoli, red pepper and zucchini and cook, stirring occasionally, for 10 minutes, until the vegetables are soft and starting to brown. Add the marinara sauce, balsamic vinegar and oregano and season generously with sea salt and freshly ground pepper.
In a medium bowl, whisk together the ricotta, egg, sea salt, freshly ground pepper and nutmeg.
In an 8-inch-square baking dish, spread 1/2 cup of the ricotta mixture and cover with half of the eggplant, in a single layer. Spread half of the marinara sauce on top and cover with half of the ricotta, sprinkle with half of the Parmigiano-Reggiano cheese. Arrange the remaining eggplant strips in a layer and top with the remaining marinara sauce and ricotta. Sprinkle the rest of the Parmigiano-Reggiano cheese on top, and dot with the fresh mozzarella.
Cover the baking dish with nonstick aluminum foil and bake in the preheated oven for 35 minutes. Remove the foil, turn the oven to broil and broil the lasagna for 5 to 10 minutes, or until the top is brown and bubbly.
Remove the lasagna from the oven and let it rest for at least 5 minutes before serving.