An old-time Sicilian favourite with a million uses. It is great warm or at room temperature, and always tastes better after a day or two. To my mind, it also makes a great sauce for pasta or couscous. It's also delicious with cheese: try spreading it over rustic bread and topping with mature vegetarian pecorino, much like the English cheese and pickle sandwich. Serves four as a condiment.
80ml olive oil
80ml sunflower oil
1 large aubergine (350g), cut into 2.5cm dice
120g celery, tender part only, cut on an angle into 2cm-wide slices
1 red pepper, cut into 1.5cm dice
1 medium onion, thinly sliced
½ tsp harissa paste
150g tinned tomatoes
2 tbsp red-wine vinegar
30g green olives, pitted and halved
1½ tsp caster sugar
Salt and black pepper
30g raisins (optional)
2 tsp lemon juice
4 tbsp chopped parsley
Heat both oils in a large, heavy-based sauté pan for which you have a lid. Lay in the aubergine and fry for five to seven minutes, until golden-brown, stirring occasionally. Use a slotted spoon to transfer the aubergine to a colander and sprinkle with a bit of salt. After a few minutes, transfer to soak on a paper towel.
Add the celery to the hot oil, fry for three minutes, add the pepper and cook for two minutes. Transfer to the colander, then to a paper towel.
Sauté the onion and harissa in the oil (add a little more to the pan, if need be) for seven minutes, until soft and golden. Drain off any excess oil from the pan, add the tomatoes and vinegar, stir and bring to a simmer. Add the fried vegetables, capers, olives and sugar, and season. If the mix is too dry, add a few tablespoons of water. Bring to a boil, cover and simmer for 10 minutes.
Remove the pan from the heat, add the raisins (if using), taste and adjust the seasoning. Leave to come to room temperature, add the lemon juice and parsley, and taste for seasoning again.
• Yotam Ottolenghi is chef/patron of Ottolenghi in London. His new book, Plenty, is published by Ebury at £25. To order a copy for £23 (including UK p&p), go to guardian.co.uk/bookshop or call 0330 333 6846.