Thickly grate carrots into a bowl. Dry grind red chillies and mustard seeds.
Heat oil in a pan, add ½ tsp mustard seeds, fenugreek seeds and asafoetida and saute till the seeds splutter.
Add carrots and mix. Add salt and mix. Switch off heat.
Add 2 tbsps of the ground mixture and mix well. Add juice of ½ lemon and mix.
Cool and store in a bottle. After a day keep it in the refrigerator. It will keep upto 2 weeks.