Firstly, in a large vessel, take 2 tbsp oil. Add 1 onion and saute well.
Add 1 tomato, 1 carrot, 1 potato, 6 beans, 10 pieces of drumsticks, 1 tsp salt, ½ tsp turmeric, 2 chillies, and a few curry leaves. Stir fry for 2 minutes.
Add 4 cups of water and boil for 5 minutes or until the vegetables are half-cooked.
Now, add ½ cup tamarind extract and 1 tsp jaggery, and continue to boil until the vegetables are cooked well.
Add 2 cups of cooked toor dal and 2 cups of water, and mix well, adjusting the consistency as needed.
Add 2 tbsp sambar powder and 1 tsp salt. Mix and boil for 5 minutes.
Now, prepare the tempering by heating 1 tbsp of coconut oil. Add 1 tsp mustard, ½ tsp urad dal, 1 dried red chilli, a pinch of hing, and a few curry leaves.
Splutter the tempering and pour over the sambar.
Also, add 2 tbsp coriander and mix well.
Finally, enjoy Idli Sambar with hot steamed idlis or dosas.