Begin by washing three large zucchinis and slicing them into 1/4-inch rounds. Sprinkle the slices with salt and let them sit in a colander for 15 minutes to draw out excess moisture.

In a large skillet, heat 1 tablespoon of extra virgin olive oil over medium heat. Add 1.5 lbs of ground turkey, breaking it up with a spoon. Cook for about 2-3 minutes until browned, stirring frequently.

Stir in one finely diced medium yellow onion and four minced garlic cloves into the browned turkey. Cook for 2-3 minutes until the onions are translucent and fragrant.

Pour in 2 cups of marinara sauce, stirring to combine evenly with the turkey and vegetables. Allow the mixture to simmer over low heat for about 5-7 minutes.

Preheat your oven to 400°F (200°C). In a 9x13 baking dish, spread a thin layer of the marinara sauce mixture on the bottom. Arrange half of the prepared zucchini slices over the sauce.

Repeat the process, alternating layers of sauce, zucchini, and finish with a final layer of meat sauce on top.

Top your casserole with 1.5 cups of shredded mozzarella cheese and 0.5 cups of grated parmesan cheese. Place the dish in the preheated oven and bake for 20 minutes.

For the finishing touch, switch your oven to broil and allow the casserole to broil for an additional 2-3 minutes.