Cook the toor dal with 1 cup water and ½ tsp turmeric powder, in a pressure cooker for 4-5 whistles.
Once the pressure is released take out and mash it well and keep aside.
Soak a lemon sized tamarind in hot water for 10 minutes and extract 1.5 cups of tamarind juice.
In a pan add 2 tsp of oil and add the coriander seeds, chana dal, fenugreek seeds and red chilis.
Roast in medium flame till the dal turns golden brown.
Add the coconut and switch off the flame.
Once it is cool grind this into a smooth paste. Add little water while grinding.
In a pan add 1 tbsp of oil and add the mustard seeds.
Once the mustard seeds splutter, add the peeled small onions.
Saute till it turns slight golden brown.
Now simmer the flame and add the tamarind water.
Add the sambar powder, ½ tsp turmeric powder, salt and asafoetida.
Let this boil for 5-7 minutes.
Now add the cooked toor dal and the ground coconut paste.
Add ½ cup of water to adjust the consistency.
Mix well and let this boil for 2 minutes.
Add 1 tsp of ghee to this. This enhances the flavour of the sambar.
Add curry leaves.
Switch off the flame and add finely chopped coriander leaves.
Vengaya sambar is ready.
Pair it with the classic potato curry and enjoy with plain rice.