Cut raw mangoes into small pieces and mix them with salt. Leave them aside for 30 minutes.
Heat some oil and add methi and mustard seeds. Turn off the heat after 1-2 minutes.
Add some red chilli powder and curry leaves to it. Stire well.
Then mix salted mango pieces, a little more salt and white vinegar.
After the mango pickle has cooled down, transfer it to a dry, airtight container.