Soak the tamarind in water and squeeze the extract out of it.
Put the rinsed toor dal, as gourd pieces, turmeric, green chillies and 1.5 cups of water in a pressure cooker and cook for 3 – 4 whistles.
Turn off the flame and wait until the pressure goes off.
Add the salt, red chilli powder and tamarind extract to the cooked toor dal mixture and let it cook for 5 minutes.
Heat oil in a pan for seasoning. Add the mustard seeds, chana dal, urad dal and cumin seeds and let them splutter.
Add the curry leaves, red chilli and hing and stir for a couple of seconds.
Turn off the heat. Add the seasoned ingredients to the dal and mix well.
Serve hot with rice or roti.