Rinse the aubergines, cut off their stalk and cut them into 1/2 cm large slices lengthwise.
Salt the slices and place them in a colander. Allow to drain for at least 30 minutes.
In the meantime, prepare the sauce. Mince the onion and garlic and sauté for 3-4 minutes in a saucepan with olive oil. Add the diced tomatoes, salt and pepper. Optional: add dried oregano and a few basil leaves. Simmer on low heat for 30 minutes, stirring from time to time.
Pat the eggplant slices dry and grill them in a pan with a little olive oil.
Slices the fior di latte mozzarella and reserve.
Cover the bottom of a casserole dish with tomato sauce, arrange the aubergine slices next to each other and add mozzarella slices on top of them. Repeat this step with all the remaining eggplant, tomato sauce and mozzarella slices.
Bake for 30 minutes at 180°C. Wait a few minutes before serving.
The most greedy will add parmesan cheese too ;-) We know who you are!