Preheat your oven to 375°F (190°C).

Slice the eggplant into ½-inch rounds and place them on a paper towel-lined tray. Sprinkle salt over the slices and let them sit for 20 minutes.

In a large skillet, heat olive oil over medium heat. Add chopped onions and sauté until translucent, about 5-7 minutes.

Add minced garlic and ground beef to the skillet. Cook until browned, about 8-10 minutes.

Stir in tomato sauce and Italian seasoning, mixing thoroughly, then let simmer for 5 minutes.

In a large baking dish, layer half of the eggplant rounds at the bottom. Top with half of the meat mixture and repeat.

Sprinkle shredded mozzarella cheese over the top of the assembled casserole.

Bake in the preheated oven for 30-35 minutes until the cheese is bubbly and golden.