Cook the rice and toor dal separately and keep them aside. Mash the toor dal well and gently mash the rice as well. I like my sambhar sadham a little on the grainy side, so I don't mash my rice too much.
Soak the tamarind in hot water ( about 2 cups) and squeeze the juice.
Chop all the vegetables and keep the ready.
Fry all the ingredients mentioned under the list and once it cools down, grind it into a smooth paste adding a little water as needed.
In a heavy bottom pan, heat 1 tablespoon of oil and add the pearl onions. Saute it for 2 to 3 minutes in medium heat and then add the rest of vegetables.
Fry the vegetables for about 5 minutes and add the extracted tamarind water.
Add the sambhar powder, turmeric powder and salt and let the mixture boil well. The raw smell of the tamarind should disappear and also the vegetables should be cooked. Make sure that the vegetables still maintain their shape and not become mushy.
At this stage, add the ground paste and mix well. Let it come to a gentle boil and then add the cooked toor dal. Mix well and let the sambhar boil for 5 to 7 minutes in low heat.
Add the cooked rice and mix well. make sure that there are no lumps in the rice.
Let the sambhar sadham simmer for 5 to 7 minutes in very low flame.
Serve hot with Appalam / Vadam / Chips.