Wash kamrakh and then wipe with a cloth napkin.
Slice into roundels,cubes or long slices as per your preference.
Dry roast fennel ,mustard and fenugreek seeds and grind to make a coarse powder.
Add all the spices in the sliced kamrakh and fill in a glass jar.
Keep it covered for a day.
Next day heat mustard oil in a pan til it start to smoke then let it come to room temperature.
Now pour this oil in the pickle jar and keep it in sunlight for 3-4 days and start using after that.
If you are making a big batch of the pickle then make sure to cover the pickle with oil till top layer.