Cut aubergine into medium chunks, sprinkle with salt and let them sweat for at least 10 minutes. Chop the remaining vegetables into medium size chunks. Finely chop the onion and garlic.
Heat oil in a frying pan, cook aubergine for 10-15 minutes or until soft. Remove and set aside.
Fry onions over medium heat until soft, then add garlic, celery, courgette, and oregano and cook a further 10 minutes. Return aubergine to the pan.
Chop baby plum tomatoes in half and add to the vegetables along with the tinned tomatoes, wine, vinegar, sugar, and a splash of water. Bring to a boil then cover and simmer for 30 minutes. (See notes for additional cooking tips)
To make the meatballs: Heat oven to 200°C.
Over medium heat, dry roast fennel seeds until fragrant, approx 30 seconds. Be careful not to over-brown or burn. Remove from the pan and grind into a powder.
Wet the breadcrumbs in a little water until they form a thick paste. Put all the ingredients for the meatballs, including the mushy breadcrumbs and fennel seed powder, in a bowl and mix well. Be careful not to crush the meat too much as this will make the meatballs tough and dry. There should still be a little bit of texture in the meat so that the fat can work its way through and keep the meatballs moist.
To test the seasoning, fry a small amount of mince in a pan. Adjust with more salt and pepper if needed. Once you are happy with the flavour, separate mince into even-sized meatballs, either circular or slightly oval-shaped.
Place on a greased tray or baking paper and roast in the oven for 10 minutes. Remove from oven.
To finish: Add meatballs to the caponata pan and spoon over the sauce so they are submerged. Cover again and simmer for a further 10 minutes.
Meanwhile, using a nonstick frying pan, gently dry roast pine nuts until lightly browned. Set aside. Next rough chop the olives and capers.
To serve: Stir olives and capers through caponata. Divide sauce and meatballs between bowls. Garnish with roasted pine nuts, freshly chopped basil leaves, and a drizzle of good-quality olive oil.