This is a stacked eggplant, tomato, smoked mozzarella, and basil appetizer. It all depends on the freshness and tenderness of the components:

There are few things in Italy where bigger is necessarily considered better: among the few notable exceptions are red wines and an abundant table. But when it comes to vegetables (ok, quit laughing now), smaller artichokes, zucchini, and eggplant are more desirable. They are more tender and less bitter.  Eggplant is very Italiano, and Mama used it in lasagne, or fried it and served with sauce, or as an appetizer. Mama chose eggplant that were not the largest, but were firm and fresh. Like all cooks of the era, she peeled, sliced and salted the eggplant to draw out any bitterness and reduce the water content. Later, techniques of steaming the whole eggplant for 20 to 30 minutes a la Julia Child became more popular. The eggplant is more watery, though less salty. Another alternative is to bake the halved eggplant for about 20 minutes at 350 degrees, but you lose the familiar round slices of eggplant to use in recipes. So choose your technique. I find young eggplant don't need the salt anyway, but if it's the end of the season, you'll probably need to use it.

Likewise, the largest tomato isn't usually the tastiest. Find a variety you like, keeping in mind that a round slice of eggplant should be not much larger than a slice of the tomato.

Basil grown fresh and picked before the end of the season is tender. Grown too late or too old and it's just tough. There are now many different varieties if you grow your own. Add your own twist.

Smoked mozzarella is an interesting variation from mozzarella. Smoked cheeses are wine-friendly Unless you find a high quality cheese, this smoked version is the tastiest.

One eggplant, firm, no wrinkles
salt
smoked mozzarella cheese
tomatoes
olive oil
basil leaves

Slice the unpeeled eggplant into 3/8' slices, salt, set aside. Slice the tomatoes to the same number but thinner than the eggplant slices. Slice the mozzarella the same as the tomatoes. Rinse the eggplant, pat dry, brush with olive oil and hot grill on both sides until tender.. Remove and top with the cheese, then tomato, then basil. Drizzle with olive oil.

Serve plated, warm or cold with red wine, such as Bambino Grande.