Heat oil in a pan
Temper mustard, curry leaves in it and allow it to crackle
Add turmeric powder, tomato, salt and cook well
Meanwhile grind tamarind, green chili, coconut into a fine paste, add as minimum water as possible
Add ground paste to cooked tomato, mix well and allow to boil, add little water if required
When boils add jaggery, mix and allow to boil for 5min
Garnish with coriander leaves
Serve hot with hot rice