In a kadai put one teaspoon oil and fry the Karamani till it turns light brown. Put it in a pressure cooker and add 2 cups of water and pressure cook for three whistles. Cool it and drain the excess water.
Squeeze out the tamarind and extract the juice. Add more water and again take out the remaining juice. The tamarind juice should be of 3 cups.
In a kadai put the oil and when it is hot add mustard. When it starts pop up add fenugreek, asafetida and curry leaves. Add chopped onion and garlic flake and stir fry for few seconds.
Add sambar powder and turmeric powder and give a quick stir.
Add tamarind water along with cooked karamani.
Stir well. Allow to cook in a medium flame till it starts boiling well.