1.Heat the oil in a large heavy-based pan.
2.Add the mustard seeds, kalonji and let it crackle.
3.Tip in the onions and saute it for a while.
4.Add the chopped ginger and chopped red chili cook for 5 mins until fragrant.
5.Add turmeric, add the dices of pine apple and saute if for a while.
6.Add the brown sugar, cider vinegar,salt cover the pan and let it cook.
7.Cook until dark golden and thick.