Wash & peel the carrots and dry them completely. You can use kitchen roll to wipe off any excess water. Cut the carrots into long thick slices, about the size of a finger.
Grind a teaspoon of mustard seeds in a mortar & pestle. Add it to the mixture.
Add red chilli powder, salt, mango powder, turmeric powder ,fennel seeds and a pinch of heeng
Then add 3 tablespoons of mustard oil. If you do not have mustard oil you can add any other cooking oil. Mix all the ingredients well. If the mixture seems dry then add more oil. Transfer the mixture to an airtight glass bottle
Store it at room temperature for 3-4 days. Mix it occasionally, around once a day. The carrots would have absorbed the spices by this time. Refrigerate it after 4 days. Gajar Ka Achar is ready.