Caramalised onion relish kittylette? Its delish and fairly instant, these measures are a bit of a guess-timate but you'll get a good result i think....
4 large onions, thinly sliced
10 tablespoons olive oil
2 tablespoons of balsamic vinegar
1/2 teaspoon of salt
1/2teaspoon sugar
Soften onions in oil add sugar and salt brownfor a while (20 to 30 mins) take off heat add balsamic vinegar, leave to cool, eat!
I use red onions too!