Rinse and chop onion and tomato.
Heat 2 tsp of oil in a frying pan. Add in red chili, gram dal and urad dal. Start roasting them under medium flame.
Roast until dal is slightly brown.
Add in chopped onion, curry leaves and coriander leaves.
Fry until onions turn translucent. Next add in chopped tomato. You can avoid tomato by adding thick tamarind juice.
Add in turmeric powder, salt and jaggery.
Fry until tomatoes turn mushy.
Wait until cool, transfer it into a mixer grinder and grind until fine.
Transfer it into a bowl.
Prepare tempering using oil, mustard seeds, red chili, urad dal and curry leaves.