Wash the aubergine, rub dry and cut into finger-thick slices (approx. 3 cm) and then spread over it with half a clove of garlic. Like bread for real bruschetta. Put 3 tablespoons of olive oil in a non-stick pan and fry the aubergines on both sides for 10 minutes. Then salt and pepper.
In the meantime, cut the tomatoes in half and remove the insides with a spoon. Finely dice tomatoes and mozzarella, halve the red onion and cut into fine rings. Add 2 tablespoons of olive oil, carefully mix everything and season with salt and pepper.
Let the aubergine slices cool down briefly and spread the filling on top.