1. To make the caponata, pour three tablespoons of oil into a large heavy based saucepan or casserole dish, place over a medium heat and add the aubergines. Cook for 15 minutes until soft. Add the remaining tablespoon of oil, followed by the shallots and cook for a further five minutes. Then stir in the tomatoes and cook slowly, so they break down and turn to a mush. Next stir in the capers, raisins, olives, celery, dried oregano, vinegar, tomato purée, season and cover with a lid. Cook over a low heat for 20 minutes until all the vegetables are soft. Stir gently so it doesn’t break up too much.