We can't stress this enough - this recipe is aching to be tweaked and customized to your tastes. Caponata are as different from house to house in Sicily as curries in India. Add more anchovies or leave them out - toss in fresh basil if you prefer - squirt in some lemon juice - there's not much you can do to muck this up.
Toss eggplant with some olive oil and roast at 350 degrees approximately 15 minutes. Saute onions and garlic until golden. Then add celery and tomato paste, along with a few teaspoons of water and simmer for 10 minutes. * (see below) Add capers, pinenuts, raisins, olives, vinegar, sugar and salt & pepper, along with the eggplant and cook for 20 minutes. Serve at room temperature as described above, or cool overnight for even better flavor.
*One point at which most recipes diverge is texture. Some prefer a crunchier caponata, which is acheived by adding celery later. Others will chop the vegetables more coarsely.
Traditionally made tomato paste is a rarity in this day. Ovens play too great a role in industrial production, rather than the old world method of drying the tomatos in the sun. Most tomato pastes are heavily-pasteurized to ease the canning process - Maria's is unpasteurized and hand-packed, the way it's always been done. (This means the lids won't be "compressed", like some jarred preserves.)
Maria Grammatico spreads the pulp of the tomatoes on taulieri, wooden boards seasoned with years of tomato-drying, and leaves it on her rooftop for just over a week. The thick, rich paste is then salted and packed into candari, large clay jars, and covered in fine Sicilian extra virgin olive oil. This ancient preservation method has worked for Grammatico and she sees no reason to change. A traditional snack for lucky Sicilian children is a bit of tomato paste spread on a slice of bread...simple, but perfect.