• Wash the tuvar dal well. Add enough water to it. Add
  turmeric powder and a drop of ghee to this. Cook it in the pressure cooker till
  it is soft and mushy.

TO MAKE THE RASAM POWDER

• Now take all the ingredients mentioned in the rasam powder
  section and keep it ready
• Add ghee to a pan and add all the other ingredients to this
  except coconut. Roast it well till it becomes light brown in colour. Switch off
  the fire and transfer it to a plate. In the same pan add the coconut and saute
  till a good flavour emanates. Switch off the fire. Now grind all of this into a
  fine powder and keep aside
• Soak the tamarind in warm water for 10 minutes. Squeeze it
  well and take out the extract and transfer it to the vessel in which you are
  going to cook the rasam
• To this tamarind extract, add the ground tomato puree and
  salt and let it boil on low flame till the raw smell of the tomato disappears.
  It will take approximately 5 mins
• Now to this boiling tamarind tomato mixture add the cooked
  dal along with 2 cups of water and let it further cook for 5 minutes
• To this boiling rasam add the prepared rasam powder, mix
  well and let it boil for 3-4 minutes
• Now add the curry leaves, coriander leaves, asafoetida and
  boil for 2 minutes. Check for salt and add if necessary
• Now switch off the fire and keep it aside
• To add the tempering, heat the ghee in a pan. Add mustard
  seeds. Once it starts to splutter add the cumin seeds and let it sizzle. Now
  add the prepared tempering to the rasam and serve warm with steamed rice and a
  curry