Preheat your oven to 375°F (190°C).
Slice the zucchini lengthwise into thin strips using a vegetable peeler or mandoline slicer. Lay the strips on a clean kitchen towel, sprinkle them with salt, and let them sit for about 10 minutes to draw out excess moisture.
In a large skillet, heat a splash of olive oil over medium heat. Add the chopped onion and minced garlic, and sauté until the onion is translucent.
Add the ground turkey (or beef) to the skillet. Cook until browned, breaking it apart with a spoon as it cooks. Drain excess fat if necessary.
Stir in the marinara sauce, oregano, basil, salt, and pepper. Allow the mixture to simmer for about 5 minutes to develop the flavors.
In a mixing bowl, combine the ricotta cheese and half of the grated Parmesan cheese. Season lightly with salt and pepper.
Begin layering the lasagna in the baking dish: Start with a layer of the meat sauce on the bottom, followed by a layer of zucchini strips, and then spread a layer of the ricotta mixture. Sprinkle a little mozzarella cheese on top.
Repeat the layering process (meat sauce, zucchini, ricotta, mozzarella) until all ingredients are used, finishing with a layer of meat sauce on top and topping it with the remaining mozzarella and Parmesan cheese.
Cover the baking dish with aluminum foil and bake in the preheated oven for 30 minutes. After 30 minutes, remove the foil and bake for an additional 15 minutes until the cheese is bubbly and golden.
Allow the lasagna to cool for about 10 minutes before slicing and serving.