Use a peeler to remove the skin from the tomatoes. For each tomato, cut a circle around the core to remove it, then cut the tomato in half. Cut each half in half again. Squeeze the tomato quarters gently to loosen the seeds and scrape them out with a knife.
Squeeze out the liquid from the tomato pieces and set them in a drainer. Pat them dry with a paper towel before adding to the caponata.
Rinse the eggplants. Cut off the root and stem ends. Peel the skin. Cut each eggplant in half lengthwise, then in half again lengthwise. If they're still very thick, you can cut them in half again. Cut the eggplant horizontally into cubes about 1.5 inches thick. (Or make them smaller for a spreadable relish.)
Chop the onion and garlic. Heat oil in a large skillet on medium high. Add the onions to the pan and cook for a couple minutes, then add the garlic. Cook until the onions are soft. Don't let the garlic burn.
Add the eggplant cubes to the pan and stir them in with the onions and garlic. Cook for about 6 minutes. Snip the basil into pieces and add them to the pan. Stir in black pepper and salt.
Add the tomatoes and vinegar to the pan and stir briefly. Put the heat on medium and cook for 15 minutes uncovered, stirring periodically as needed to prevent sticking.
While the caponata is cooking, drain the olives and dry them on paper towels. When the caponatina is finished cooking, remove the pan from the heat. Add the olives and sugar to the eggplants. Stir to combine.
Place the caponata in a serving bowl, cover it and refrigerate it, ideally overnight. Before serving, stir the caponatina and taste to see if it needs any salt. Be sure to try it with the olives, which will add a salty flavor. Serve cold or at room temperature as a side dish or on crostini for an appetizer. Use a slotted spoon to scoop it out of the bowl.
Store leftovers in the refrigerator, covered tightly, for up to five days. I would not freeze it.
Notes
It's important to use nice eggplants for this recipe. No mushy ones allowed!If you don't see good ones at the market, ask a produce worker to bring out more eggplants from the back. You can then go through the box yourself to pick the best ones. #italiancookingsecretsChoose eggplants that are:
Glossy and firm, not bruised.
With green tops, not brown.
Small and skinny, if possible, because they are younger and usually have less seeds, which are bitter.
There are myths about the existence of male and female eggplants and how looking at the shape of the dimple on the bottom can identify which ones have more seeds. Just remember, the heavier the eggplant, the more seeds it probably has.If you discover yours have tons of seeds, you may want to remove some.A note about the tomatoes:You will need to peel and seed all the tomatoes, then squeeze them dry so they don't make the salad runny. Prepping the tomatoes takes 30 minutes if you're doing this alone, so try to recruit an extra pair of hands, if you can.Some recipes call for tomato sauce instead, but we love fresh tomatoes here. We haven't tried using canned, peeled, tomatoes in the caponata, but that might be worth experimenting with, if you get rid of the seeds and juice.Olive oil: We use regular olive oil, since it's more mild than extra virgin. If you use extra-virgin olive oil, you may need a little extra sugar.