My introduction to caponata, when I was a teenager, was a supermarket version from a shelf somewhere near the tinned sardines and anchovies. It came in a distinctive disc-shaped glass jar, about 4 inches in diameter and an inch deep. The clamped-on lid was imprinted with an ornate logo, and somewhere it said “product of Italy.”
If you turned the jar over, you could see a mosaic of stewed vegetables in an oily tomato-y sauce, a perfect portion for one. Sometimes there was a chunk of tuna in the middle, and sometimes not. The way to open it, if you didn’t have a can opener, was with a coin — a quarter worked best. Inserted correctly between the lid and the jar, it would pop the lid right off with a twist.
Usually, the mixture was eggplant, celery and carrots, but sometimes, it was more varied. Some jars contained more of an assortment of vegetables: perhaps a fava bean, a bit of cauliflower, a wedge of artichoke. The dressing was sweet and tart, and the vegetables were soft enough to spread on bread.
In truth, commercially canned caponata is nothing to sneeze at. It’s always tasty, although the oil used may not be first quality. Home-canned caponata made with extra-virgin olive oil and freshly picked vegetables is deluxe. The vinegar in the sauce makes it somewhat like a pickle or preserve, and it’s a treat to have a few pint jars in the pantry to eat out of season.
Sicily claims caponata as its own, though it seems as if every restaurant and home cook has a different variation. The island grows tons of eggplant, so it is a constant in caponata — except when it’s not. I have a Sicilian friend who makes it with artichokes. Another friend makes it with just zucchini. Some cooks use a little tomato, others a lot. Often the mix includes peppers and is a bit like ratatouille with an Italian accent.
For sweetness, most cooks add a bit of sugar; many add raisins or currants. For tartness, a splash of vinegar and a few capers go a long way. You can’t stint on the oil or be timid with the seasoning.
If possible, wait a few hours before you eat it, to allow the flavors to mellow and meld. Or better yet, leave it in the refrigerator, for a day or more. Just be sure to serve it at room temperature.