Heat the olive oil in a medium saucepan and add all the ingredients. Cover the pan and cook over a medium low heat for about 30 minutes until the vegetables are soft, stirring from time to time to make sure they dont stick.
Remove the lid and crush the vegetables with a potato masher, then leave to cook for a further 5 minutes over a medium heat, stirring occasionally, until all the liquid has evaporated. Check seasoning.
Serve warm or cold, garnished with a sprinkling of coriander.