Peel the raw mangoes, slice them and keep the seeds aside. The seeds can be discarded. Finely chop the mango flesh into small cubes.
Salt it well and keep it for a day to marinate.
Finely chopped ginger and garlic and keep aside.
In a heavy bottom pan, boil some vinegar with the chopped ginger and garlic, chilli powder and sugar for about 5 mins.
Next add the raw mango and cook on a low flame until the gravy thickens and the mango is cooked and soft to eat.
Check for taste and add more sugar or salt if required. You can also add more chilli powder if you like it spicy.
Once ready, bottle it up and enjoy with some nice hot chapatis or papad.