Wash raw mangoes and then wipe them properly with a cloth.
Remove the seed and slice into medium size pieces .
In a big bowl add mango pieces ,salt and turmeric and mix well.
Keep covered for 2 days and mix once in a day.
After adding salt, mango pieces release some water so collect that water in a separate container.
Now spread the mango pieces on a cloth or in a big plate.
Keep the mango pieces and the bowl in which we have collected the water in sunlight.
Keep both (water and mango pieces) in the sun for 2 days.
Dry roast fenugreek seeds and crush to make a coarse powder.
Lightly crush or pound mustard seeds and fennel seeds.
Now after 2 days mix jaggary in that water and mix well to dissolve it completely.
Heat mustard oil to a smoking point then let it cool down completely.
Add all the spices in the mango pieces and then add the oil and mix.
Now add the jaggary water in the mango pieces and mix.
Fill the pickle in a ceramic or glass jar and keep covered for 2 days.
Now cover the mouth of the jar with a muslin cloth and keep it in sun for 3-4 days.
Stir and mix it once in a day for a week.
After 15 days its ready to use .