1. Heat a pan add 1/2 tsp oil, roast chana dal, red chilly, urad dal, coriander seeds, methi and jeera, in this order. so that it doesn't get over roasted. once it cools powder it.
2. Wash and chop the citron lemon into small pieces. remove seeds. soak tamarind and take the pulp. keep it aside.
3. Heat a kadai and add oil. once hot add mustard seeds and let it splutter. add hing, red chilly, chopped heralekai (citron) and salt.
4. Saute and cook it covered, after about 5 mins add jaggery mix it and cook it again covered until it's soft. once it's soft and cooked add the tamarind pulp and the powdered masala.
5. Mix it and add 3 tbsps water and cook it, until it's thick and completely dry. this can be stored for 3 to 4 weeks in the fridge.
6. This goes well with rasam rice or curd rice or even rotti, chapati. i learnt this from my husband's aunt.