I find cabbage loses its identity in a curry, but there's another way; stir fry it quickly on its own in a little ghee or butter, then reduce the heat and add a drop of water so the cabbage finishes cooking by steaming. Meanwhile, melt a little ghee in a separate, small pan. Just when you're ready to serve the cabbage, drop a few cumin seeds into the ghee, then pour it over the cabbage.