Cook the brinjals on a hot plate or over a flame as follows: Place the brinjals on a heated solid hot plate and leave to cook until they start to collapse and the skin becomes blackened and dry. Turn regularly to ensure even cooking.
Alternatively, stick 2 forks into each brinjal and hold above the flame of a gas burner. Cook until the skin starts to blister and the brinjal wrinkles and collapses. There will be a strong smoky smell.
Peel and wash the brinjals. Squeeze out the bitter juices.
Process the brinjal flesh and garlic to a creamy purée in a food processor.
Add the tahina and lemon juice alternately, blending well after each addition.
Add the cumin, coriander, salt and pepper to taste.
Pour the purée into a serving dish and garnish with coriander leaves, olives and tomato wedges.
Serve with flat breads.