Cook the toor dal in a pressure cooker for 4 whistles or in a large heavy-bottomed pot by covering with 2 cups water and simmering until very soft. Use a spoon to beat the dal so it disintegrates and creates a thin-ish stock.
While the dal is cooking, prepare the raw tamarind “chutney” by breaking the tamarind and either pounding it with a stone or pulsing it in a blender jar until it’s a semi-smooth paste, along with the garlic (if using) and dry red chillies. A few chunks and a little texture are good things! Remove any visible fibres.
Once the dal is cooked, transfer to an eeya chombu or other heavy-bottomed pot. Add more water until the eeya chombu is about ¾ full [you should have ¾ litre of liquid, total]. Bring this to a boil on a low flame.
Add scant ½ teaspoon turmeric
Add the chutney paste. Wash the grinding stone or mixie jar with a little water and add this, too.
Roast the jeera and black pepper lightly, and crush into a coarse paste. Add this to the chaaru along with the rasam powder.
A generous chunk of jaggery goes in next, followed by salt.
Keep the heat on low and continue cooking until the chaaru begins to foam and froth.
Then work quickly to temper. Heat a spoonful of ghee in a small tempering pan. Once it’s very hot, drop in a ¼ teaspoon each mustard seeds and jeera, a pinch of hing, a broken red chilli. Let these splutter and pop. Follow with curry leaves for a few seconds, and pour this finishing oil directly on top of the foaming rasam.
Turn off the heat and mix well.
Garnish with a few tender tamarind leaves or coriander
Serve with a soft white rice and a potato or yam poriyal. Fried raw banana works well, too!
