Put it in a pressure cooker along with the onions, tomatoes, garlic, chilli powder, turmeric powder, salt and water.
Pressure cook it for 10 minutes on medium flame. I pressure cooked it for 2 whistles.
Take it off the stove.
Once the steam is released fully from the cooker, open it and stir the gravy.
Place it on low heat and add the tamarind paste and boil well.
Take a separate pan for tempering the dish.
Heat the oil. Add the red chillies.
Once it changes colour, add the asafoetida and pour it onto the boiling gravy.
Serve Hot!
Notes
Adjust the level of the tamarind depending on how concentrated your tamarind paste is. Start with half a teaspoon and increase it till it reaches your comfort level. Increase spice level to taste. Add more water if you don't want the gravy to be thick
Recipe by Spice Counter at http://spicecounter.com/sides/manathakkali-kootu/