Soak the tamarind in hot water for about 15 minutes and then squeeze out the extract.
Cook the tuvaram paruppu in a pressure cooker until very soft and mushy. Once cooked, mash it well with a ladle and keep it aside.
Peel the pearl onions are using fresh ones. I used frozen ones and all I had to do was drop it into the pan.
In a pot, add about 2 tsp of oil (preferably gingelly oil) and sauté the onions for about 5-7 minutes, until aromatic.
Now add the tamarind extract, sambhar powder, and salt and let it boil for about 10-15 minutes.
In the meantime, in a small pan, fry all the ingredients (except coconut) mentioned under grind together to about golden brown. Then add the grated coconut and fry for a minute more until it is lightly golden.
Let it cool down a bit and then grind to a coarse paste using very little water. Keep it aside.
Check and see if the vegetable is cooked and then add the ground paste. Let it come to a quick boil and then add the cooked paruppu/dal. Mix well and add a little more water (if needed) to adjust the consistency. Also add the curry leaves now and let it simmer for about 8-10 minutes. Stir it often in between since the sambhar tends to settle down in the bottom.
Heat oil for seasoning and then add the ingredients mentioned above. Add the seasoning to the sambhar and then turn off the flame.
Serve hot with rice and ghee!