Caramelizing onions takes a long time - you do this over low heat with a bit of water, butter, and sugar. As the water evaporates, the onion continues to cook - you keep adding water to prevent the onions from burning - the long cooking process is to draw out the natural sugars of the onion.
My version's a bit modified - instead of using sugar, I used kecap manis, an Indonesian sweet soy sauce. I had assumed that one sugar would work as good as the next; the problem, of course, is that the soy sauce was brown - I couldn't really tell if my onions were caramelizing or if it was just coated with soy. In either case, this dish turned out well - the spiciness from the sriracha paired nicely with the sweetness from the onions and kecap manis.
