Slice the aubergines lengthways and arrange them in a wide colander. Scatter over plenty of salt and put a plate on top. Place a heavy weight on the plate and leave them for 1 hour to drain out all their bitter juices.
Heat the oil in a deep-fat fryer to 195°C (385°F). Meanwhile, drain, wash and dry the aubergine slices. Fry them quickly in the oil until crisp and golden, then drain on