My first attempt at the banjara was with ordinary onions which were a bit watery and obviously past their best, they went from quite well done, almost caramelised, to burnt to a crisp in the blink of an eye and stunk the house out for days. Tried again with good red onions, no problems twice now, so I would say use good onoins (red or white but red tend to be less watery generally) and take your time, if you try to rush it you will most likely end up with a burnt bitter mess. It also helps to use a good heavy skillet with even heat distribution and once again remember, nice 'n slow, way to go. hth.