Sprinkle the aubergines with salt and leave to drain in a colander for 30 minutes.
Heat some of the olive oil in a saucepan and brown the aubergine on a moderate heat for 10 minutes. When cooked, set aside and allow to cool to room temperature.
In a separate saucepan, heat the remaining olive oil and sauté the onion along with the celery and tomatoes. Season with salt and freshly ground black pepper. Add the olives and cook for 20 minutes.
Add the cooled aubergine and the capers.
In a separate bowl, mix together the red wine vinegar and sugar. Add this to the pan and cook for 10 minutes. It is ready when the red wine vinegar has been absorbed.
Transfer to a large bowl, add the chopped parsley and mix well.
Drizzle with extra virgin olive oil to serve. Serve hot or cold.