Wash the raw mangoes and wipe them dry with a clean cloth.
Cut mangoes into quarters, remove the tender seeds, then cut into smaller pieces and put into a large bowl.
Dry roast all the seeds and Cinnamon sticks in a non-stick pan to remove the moisture and until aroma comes out.
Crush fennel seeds and fenugreek seeds.
Add salt, turmeric powder, crushed spices, split mustard seeds, red chilli powder, onion seeds, jaggery and chickpeas to the raw mango pieces and mix well thoroughly.
Heat mustard oil in a non stick pan till it starts to smoke.
Set aside to cool, when cool, add half of it to the mango mixture and mix well.
Keep the bowl covered with a muslin cloth in the sun for 2 days.
Transfer into a porcelain or a ceramic jar or glass jar and add the remaining oil so that all the mango pieces are well covered with mustard oil.
Keep this pickle in the sun, covered for further 7-8 days, keep turning the pickle upside down regularly with the help of a dry spoon.
Pickle will be ready as according to the intensity of sunshine.
Serve yummy tangy chatpata raw mango pickle with paranthas, poori or anything you like.
Store it in airtight container, preferably glass container for months and enjoy as and when required.