Preheat your grill. Brush eggplant slices with olive oil and place them on a baking tray. Cook under the grill, about 15cm from the heat for 10 minutes, or until tender and toasted.
Split the bread rolls lengthways, and toast. In a cup or small bowl, stir together the mayonnaise and garlic. Spread this mixture on the toasted bread. Fill the rolls with eggplant slices, tomato, feta cheese and basil leaves.