• 4 tablespoons olive oil
• 2 large onions, chopped
• 2 garlic cloves, crushed

Heat the oil in a large pan and fry the onions until golden. Add the garlic and cumin and stir. Add the courgettes, vinegar, salt and pepper to taste, chilli powder, if used, and tomatoes. Cover the pan and steam over a low heat for 10 minutes or until the courgettes are very tender.

Mash the mixture with a fork or a potato masher. Serve cold.