c("Heat the oil in a heavy based pan and stir in the onions to coat them  with oil, then sprinkle with the sugar and cook for 5 minutes or until  translucent. Add the vinegar and olives, season and simmer for a  further 2 minutes.", "Remove from he heat and stir in the butter.", "Sprinkle with parsley,  then check the seasoning and toss with hot pasta.", "This sauce can also be served with cold pasta.")