Wash and dry ber completely and leave them on a dry cloth under the fan
Dry roast cumin, fenugreek, fennel seeds and make a coarse powder, take out in a broad bowl
Add split yellow mustard seeds, chilli powder, turmeric, asafoetida and salt.
Add 3 tbsp oil to this masala
Now take ber and press then slightly
Add them to prepared masala
Add jaggery and mix gently
Take a clean and dry glass bottle, add half cup mustard oil, coat entire bottle from inside with oil
You can add a tea spoon of salt at this point, this will ensure that pickle doesn't get fungus in future
Now fill the bottle with prepared achaar
Top it up with remaining oil.
Leave it in sun light for a week. After that it will be ready to eat.