Salt the aubergines before cooking them by placing them in a colander and tossing them in the 2 teaspoons of salt. Place over a bowl or in the sink, then leave for 30 minutes. Wash the slices under the tap and pat dry.
Meanwhile, heat half the olive oil in a frying pan and cook the onion and garlic until brown. Add the tomato and the spices and cook over a medium heat for 8 minutes before mixing in the sultanas.
In a large frying pan, warm the remainder of the oil over a high heat then cook the aubergine on both sides till tender and golden. Stir in the onion mixture, season and chill in the fridge for at least 1 hour. To serve, pour away any excess liquid and mix in the fresh herbs.