Begin by slicing the zucchini into thin rounds. Sprinkle lightly with salt and let sit on paper towels for about 15 minutes.

Heat olive oil in a skillet over medium heat. Add the chopped onion, cooking until it’s soft and translucent—about 3-4 minutes.

Add the minced garlic and stir for an additional 30 seconds until fragrant.

Add the ground beef to the skillet, breaking it apart as it cooks until browned—approximately 5-7 minutes.

Drain any excess fat, then mix in the crushed tomatoes, Italian seasoning, salt, and black pepper.

Allow it to simmer for 5-7 minutes to meld the flavors.

While the meat sauce simmers, preheat your oven to 375°F (190°C) and lightly grease a 9×13-inch baking dish with olive oil.

Spread half of the meat sauce evenly in the bottom of the prepared baking dish.

Layer the zucchini slices over the sauce, followed by half of the shredded mozzarella and grated Parmesan cheese.

Repeat these layers.

Place the dish in the preheated oven and bake uncovered for 25–30 minutes.

Once baked, let the dish rest for about 10 minutes to set before slicing.