Skin the mango keep the skin in another bowl and add 200ml water. Squeeze the skin of all the juices, keep liquid, throw out the skin. Set aside. The whole mango with seed, salt and Chilli powder, put into a vessel and cook on low flame. Take a small shallow frying pan and heat the oil. Season with mustard seeds, curry leaves and garlic. Add the sliced onions and the ground masala, stir fry. Add this to the mangoes in the vessel. Now increase the flame to medium heat and cook for 1-2 minutes, adding the jaggery syrup.