Soak tamarind in quarter cup of water for 10 minutes and extract it's juice discarding the residue.
Pressure cook pigeon pea lentil till mushy for 3 whistles and keep it aside.
Method
Heat a pan adding all the seasoning ingredients in the order mentioned, let the mustard seeds pop up and then include the snakegourd cubes. Saute for a while.
Include tamarind juice and some water. Let the snakegourd cubes cook till soft.
Meanwhile grind grated coconut, green chillies and cumin seeds to fine paste. Add water as required.
Ensure snakegourd cubes are cooked well and include ground paste as well as cooked toor dal. Combine everything together adding water as per the desired consistency. Finally add salt and bring it to boil.
Snake gourd kootu /curry is ready. Serve it as side dish with rice. It's yummy.
Notes
You can pressure cook snakegourd cubes too, in that case add seasoning at the end.
Snake gourd cubes should not be cooked till mushy, as the veggie is very soft gets cooked very fast.
If you prefer, you can increase the quantity of toor dal and reduce grated coconut. This combination also gives a unique taste.