In a mortar add black pepper, cumin seeds and make a coarse powder. Now add in garlic cloves and crush it to make base masala.
Cut tomatoes into small pieces and mash them with your hands.
In a pan heat some oil and add in asafoetida, mustard seeds, fenugreek seeds,dry red chilli and roast it well.
Once mustard seeds start popping add in turmeric powder and 80% of the base masala.
Mix everything and lower down the heat or else masala will burn.
Once roasted add in mashed tomatoes and cook till tomatoes are soft.
Now add in tamarind water and extra water if required.
Now add in curry leaves, salt and give it a good mix and let it come to boil.
Add rest of the base masala and finely chopped coriander leaves and mix well.