Dice the eggplants into 1 1/2 - 2 cm cubes. Put them on a colander and sprinkle some rock salt in between, this will force the bitter liquid that is inside to exit. Put a weight on top and leave it for a minimum of 2 hours.
After 2 hours, brush away the rock salt and reserve the diced eggplant.
In a heated pan add the pine nuts and let them brown a little to release the flavor, set aside.
In the same pan put some extra virgin olive oil and fry the eggplants for a few minutes until they brown a little, set aside.
Cut celery in 1 cm pieces, put them in a pot of boiling salted water for 3-4 minutes. Then drain and let them dry.
Briefly fry celery in the pan with some extra virgin olive oil and set aside.
Rinse capers to remove the salt and slice olives into desired size.
In the same pan add extra virgin olive oil and the diced onion, let them brown and add tomatoes. Cook for 10 minutes and then add sugar and vinegar.
Stir for 1 minute to evaporate the vinegar. Add the other remaining ingredients and basil leaves, stir to mix together for 1-2 minutes.
Let cool, serve and enjoy.

1 kg/2.2 lbs eggplant
3 stalks of celery
250 g/9 oz onion
100 g/3.5 oz black olives, pitted
50 g/1.75 oz capers, in salt
60 g/2 oz pine nuts
500 g/1.1 lb tomato sauce or diced canned tomatoes
50 g/1.75 oz sugar
50 g/1.75 oz white wine vinegar
A few leaves of basil
Rock salt
Salt and pepper, to taste
Extra virgin olive oil, to taste