Thinly slice the eggplant and onion.
Heat olive oil in a pan and sauté the onion and minced garlic.
Add ground beef and cook, then pour in tomato sauce and simmer.
Season the eggplant with salt and pepper.
In an oven-safe dish, layer eggplant, beef tomato sauce, and mozzarella cheese in that order.
Sprinkle Parmesan cheese on top.
Bake in a preheated oven at 180°C (356°F) for 20 minutes.