Grind the tomatoes into a puree and reserve ½ portion of the tomatoes before grinding.
Finely chop that ½ portion and keep it aside.
Roast the toor dal, black pepper and red chili in ½ tsp ghee.
Once the dal turns golden brown, switch off the flame
Add the cumin seeds and mix well. Let this sit in the pan for few minutes.
Allow it cool completely and grind into a fine paste by adding little water.
Add the tomato puree in a vessel in which you are going to make rasam.
Now add in the grind paste to this.
Add ½ cup water to it and add turmeric powder, salt and asafoetida.
Let this boil for 5- 7 minutes.
Mix the cooked toor dal and 1.5 cups of water.
Add this to the pan. Let this froth up.
Add coriander leaves and few curry leaves.
In a pan add 1 tsp ghee and temper ½ tsp mustard seeds and curry leaves.
Once it splutters, add it to the rasam.
Add the chopped tomato to this.
Switch off the flame.
Kalyana rasam is ready.