In a pan dry roast fenugreek seeds till crunchy and aromatic. Transfer to a blender jar.
Next, dry roast fennel seeds till aromatic and slightly brown. Transfer to the blender along with fenugreek seeds.
Also, dry roast mustard seeds and transfer to blender jar.
Let all the spices cool down and grind them coarsely. Set aside.
Meanwhile, heat mustard oil till smoking point. Switch off the flame and let it cool a bit.
Add asafetida (hing) and mix well.
In a mixing bowl add washed, dried and cut raw mangoes.
Add turmeric powder, red chilli powder, salt, store-bought pickle masala, grounded dry roasted spices.
Finally, add oil (mixed with hing).
Mix everything well together.
Transfer to an air tight container and refrigerate. It will stay fresh for a longer time (15 days).
If you want to preserve it for 4-6 months, top it with smoked (and cooled) mustard oil till 1.5 inches above the pickle.
Serve along with Indian meals.