Soak the tamarind in hot water and extract to a thick pulp.
Take it in a thick bottom pan or kadai, bring to a boil and cook till it reduces to almost a thick liquid but not a paste.
Heat a nonstick pan, add oil, temper with mustard, chana dal, hing, curry leaves, green chilli, ground nuts, cashews and saute for a couple of minutes
Add the tamarind extract and add to the pan. Add water as required. Add turmeric powder and salt, bring to a boil
Cook on high for 10 mins, then simmer till the paste becomes thick.
Mix the spice powder in 1/4 cup water and add to the above simmering paste and mix well. Next add jaggery and combine well.
Cook in low flame for 10 mins. Allow to cool and store it in an airtight container for over a month.