Heat oven to 190C/fan 170/gas 5. Toss the eggplant in the oil in an ovenproof dish or roasting tin, and season. Roast for 20 mins until starting to tenderise and brown.
Stir in the capers, olives, tomatoes, vinegar and sugar. Cook for a further 20 mins, stirring occasionally, until everything is soft. Serve warm or at room temperature on top of toasted gluten free ciabata.