Wash dals and pressure cook with 2 cups water. Mash the cooked dal.
Heat 1 teaspoon oil in a pan over medium heat and roast all the ingredients given under the section "To roast and grind" until a fine aroma wafts. When dal turns golden brown, add curry leaves, desiccated coconut and turn off the heat. Sauté the coconut in the heat of the pan. Cool down and grind to a fine paste adding required water.
Heat 1 Tablespoon oil in a heavy bottomed pan.
Add mustard seeds and dry red chillies. Once the mustard seeds pop, add asafoetida, curry leaves, turmeric powder and a little sambar powder. Add the small onions and stir until the onions turn translucent.
Now, add the chopped tomatoes and cook for a minute.
Add the tamarind extract followed by the ground paste.
Mix well and cook on low heat for 2 minutes.
Add mashed dal, thin with some water, add jaggery, season with salt and boil.
Turn off the heat and garnish with coriander.
Serve with rice, idli, dosa, pongal.