Soak Toor Dal in warm water for 30 minutes. Add a pinch of turmeric powder and pressure cook for 3 whistles
In a heavy-bottomed pan add tomatoes, green Chilli, turmeric powder, ginger powder, salt and 1 cup of water
Boil for 10-12 minutes till raw smell goes off
Add cooked dal and 1/2 cup of water, mix well
Sprinkle chopped coriander leaves and pinch of sugar; mix well
Cook till the rasam becomes frothy
Finally add generous hing and switch off
In a small pan add ghee when the ghee is hot add mustard seeds and let it splutter
Add it to the rasam
Add a pinch of salt and squeeze a lemon; mix well
Add the lemon juice when the rasam is cool