Take a pressure cooker add add roughly chopped onions, green chillies, garlic and tomatoes.2.Add chilli powder,sambar powder needed salt with 2 cups of water.3.Close lid and pressure cook for one whistle.4.Switch off and open when pressure subsides.5.Cool the mixture add the onion mixture alone and grind smoothly reserve cooked water for the gravy.6.Keep a kadai add oil with mustard and sombu to splutter with red chillies and curry leaves.7.Add asafoetida then the ground mixture with reserved water.8.Make slurry with roasted gram flour and keep ready.9.When sambar boils add the slurry and leave to thicken.10.When it comes to sambar consistency switch off.11.Add some chopped coriander and serve hot with idli or dosa.
Notes
Use tangy tomatoes for balance of taste for this particular sambar.
We are using both chilli powder and green chillies so, be noted.
Add roasted gram flour as much you may need in moderation to thicken the sambar