1- Heat grill, chop aubergine in small cubes, place in a bowl of salted water for 10-15 mins. Then drain.
2- Place the aubergine in a roasting tin and drizzle with some olive oil. Put under the grill and roast for 5-10 mins until turning crisp. Turning once or twice. Then put aside.
3- Boil pasta depending on packet instructions. in a pot heat up some olive oil and add chopped onions and fry until golden. Add tomato puree and 3/4 roasted aubergine. Season with salt and pepper and oregano, bring to simmer for 10-12 mins.
4-Liquidise sauce, add tuna and mash slightly with a fork if too lumpy. Pour sauce over drained pasta and mix well.
5- Place a portion of pasta on a plate and decorate with chopped olives and remainig aubergine cubes and sprinkel with chopped parsley or fresh basil leaves. Serve with grated parmesan cheese.