Pierce the skin of the eggplants to prevent their skins from bursting & grill them with the peppers over moderate heat on the barbecue for 15 minutes, turning several times.
Score the skin of the tomatoes with a cross. Grill for 5 minutes, turning occasionally.
When the skins of the peppers are blistered & charred, remove from heat. Wrap in a towel & place in a paper bag. Set aside.
When cool, peel the peppers & eggplant & remove the pepper seeds.
Peel the tomatoes. Slice the vegetables. Arrange the vegetables on a platter with the tomatoes in the center.
Toss together the dressing ingredients. Drizzle the dressing over the vegetables. Serve hot or cold as a side dish or as a main course with bread. Or, combine with other tapas.
NOTE: While these vegetables are best cooked on a grill they can be cooked under the broiler.