Heat 2 tsp oil in a Kadai, roast everything given under "To Roast and Grind - Set 1". Fry until onions are completely brown. Transfer it to the mixer.
Heat 1 tsp oil in same kadai, roast roughly chopped toamtoes. Once it turns mushy. Add Sambar powder and saute until oil oozes out.
Transfer it to the same mixer and grind both set 1 & 2 to a fine paste.
Heat 1 tsp oil in a cooker, splutter mustard seeds, saute chopped onions and saute until onions turn brown.
To this add the ground masala, turmeric powder, salt and required water.
close the cooker and Cook it in simmer for 15 mins or until 1 whistle whichever is first.