Heat the grill (broiler) or barbecue plate to medium. Cut the chillies in half lengthways and use a teaspoon to scrape away the seeds. Pierce the eggplants and tomatoes with a skewer a few times and rub some of the olive oil over their skins.
Put the chillies, eggplants and tomatoes on a baking tray and place under the hot grill or on the barbecue plate. Grill, turning occasionally, unt