Recipe Instructions

Heat oil in a large frying pan over moderate heat. Add onion; cook and stir for 3 minutes or until soft. Add sugar and vinegar; cook and stir for 4 minutes or until onion caramelises. Transfer to a heatproof bowl. Meanwhile, place frankfurts in a large saucepan. Cover with cold water. Bring to a simmer over moderate heat. Simmer for 5 minutes or until heated. Using tongs, transfer frankfurts to a heatproof plate. Fill each roll with some of the onion mixture, then a frankfurt. Serve drizzled with tomato sauce and mustard.