Chop the tomatoes in quarter. In a blender add Tomatoes, chilli pd, sambhar pd, dhania pd, til seeds, Cumin seeds, grind them to fine paste.
Take a pan add oil and put mustard seeds and curry leaves – once they flutter add the paste which has been grinded. Wash the blender well with 3 cups of water and add this water to the pan with the paste. Mix well.
Finely chop the onions and add this to the mixture which has been kept to boil ( Donot fry the onion in oil as the taste will differ). Add the salt, sugar, turmeric pd at this stage and let it boil for 5 mins.
Once you see the the onion has become transperant – Make a mixture of cornflour and Coconut milk pd in 1 cup of water and mix well. Add this mixture to the boiling sambhar. Keep stirring .
You will see the sambhar will become thick consistency. You can adjust the consistency of sambhar as per your requirement. Now let this mixture boil for 3 mins nicely. Remove from fire and garnish with Coriander leaves
Serve hot with Idlis / Medu Vada. Note : Donot add Hing to this sambhar as it won’t taste good.