Cut the eggplant into cubes and put them in a colander.
Sprinkle with coarse salt, cover with a cloth and let it drain.
In the meantime, wash the celery, cut it into small pieces and put it in a pan with water.
When water has completely evaporated, add the chopped onion and fry in plenty of extra virgin olive oil.
Add capers (after desalting them), olives cut in half and tomato puree.
After adjusting for salt, cook over low heat until a rather thick sauce is obtained.
Add vinegar and sugar, stir and remove from heat.
Dry the eggplant cubes by dabbing them with a clean cloth then fry them in plenty of hot olive oil.
Once golden, remove the eggplant from heat with a slotted spoon and place it on kitchen paper.
Add the eggplant to the caponata sauce, mix well, let it cool and serve with fresh basil leaves.