Cut mangoes into half.
Remove the seeds and cut them into small pieces.
Heat oil in a pan and add mustard and hing.
When they crackle, add the mango pieces and sauté for two or three minutes.
Add salt, red chilly powder and cook for one more minute.
Add the jaggery and let it melt and mix well.
Finally add the roasted powdered methi and mustard powder and mix well.
Switch off flame and let the pickle cool down.
Transfer to a jar and refrigerate and use.