Cut the aubergines lengthways into thin slices and season with pepper. Brush a baking sheet with olive oil. Place aubergine slices next to each other and drizzle with 3 - 4 tablespoons of olive oil.
Bake in the preheated oven on the middle rack at 250 ° C for about 5 minutes. Turn in between, then take out and season with salt.
Cut the tomatoes into slices, spread them on the aubergine slices, season with salt and pepper. Grate the parmesan. Chop the sage and rosemary. Scatter herbs and parmesan over the tomatoes. Cut the mozzarella into thin slices and spread on top. Bake in the oven at 200 ° C for about 15 minutes.