Cut the cleaned ginger in round slices. Fry them in coconut oil, till it's golden brown.
Crush the fried ginger using a mortar and pestle.
Add 2 tbsp of water to tamarind and make a pulp. Add chilly powder, coriander powder, jaggery and salt. Mix well.
Add crushed ginger and 1/2cup of water to this and mix well.
Heat oil in the same pan (you can use the remaining oil) in which you fried ginger and splutter mustard. Add curry leaves and the tamarind, jaggery & ginger mixture. Let it boil till it becomes thick, around 8 - 10 mins. Add fenugreek powder & mix. Remove from fire.
Notes
Once it is cooled completely, you can store it in an airtight container in the fridge for for a week or so.