Wash the mango and cut them into pieces (either long or small pieces). Generally, Mangaloreans cut the mangoes lengthwise and make long pieces.
Cut the chillies lengthwise.
Now, take a sterilized glass or ceramic bottle.
Drop some mango pieces into the jar.
Add few pieces of chillies.
Add salt.
Keep adding mangoes, chillies and salt in layers.
Add water and close the lid.
Keep this aside untouched for 3 to 4 days.
After 4 days, the mango skin turns olive green in colour and it is ready to use.