Tuvar Dal - 1/3 cup
Tamarind - a small marble size, extract about 1 3/4 cup of tamarind juice from the tamarind
Salt - according to taste
Rasam Powder - 1 1/2 to 2 tsp
Turmeric Powder - 1/4 tsp
Pineapple - 1 1/2 cups, crushed with juice
Ghee - 1 1/2 tsp
Mustard seeds - 1 tsp
Cumin seeds - 1 tsp
Cilantro Leaves - 1 tbpsn, for garnishing
Pressure cook the tuvar dal with just enough water to cook (about 1/4 cup water approximately) or alternatively cook the tuvar dal on a stove top until very soft and mushy. Keep aside.
Place the tamarind water in a heavy bottomed pan and add salt, rasam powder, turmeric and let it boil. When it starts to boil, lower heat and add crushed pineapple with juice to this and let it simmer for about 15 to 20 minutes until the tamarind loses its rawness and the pineapple absorbs the spices a little.
Now add the mushed soft lentil to this, add some more water according to your preference and consistency required and simmer for another minute or so.
Heat the ghee in a pan, add mustard seeds and cumin seeds to it. When they start to splutter pour them into the rasam.
Garnish with cilantro and serve hot on top of plain rice or as a soup.