Ingredients
2" piece of ginger
2 large balls of tamarind
12 cloves of garlic
3 red chillies
3 green chillies
1/2 tsp methi (fenugreek) seeds, roasted finely
1 tsp mustard seeds, for seasoning
1 tsp cumin seeds
A small piece of jaggery
Salt to taste

Method
Roast the cumin seeds lightly and powder to a fine paste 
with the red chillies and half the fenugreek and garlic.
Chop the ginger, green chillies and remaining garlic.
Soak the tamarind in some hot water and extract the juice.
Put in the chopped ingredients and continue boiling.
In a  pan, heat 3 tsp oil and add the mustard seeds and the 
remaining fenugreek seeds. 
When the mustard crackles, add the ground masala and fry 
till the masala turns color.
Put in the chopped ingredients, jaggery, salt to taste and tamarind juice.
Bring to a boil and boil till the juice is thick.
Bottle when cool.
Should keep for about a week.