Wash tomatoes and cut 300gm of tomatoes into smaller pieces
Grind rest 700gm of tomatoes
Heat 100ml of oil in a pan
Temper mustard in oil
Add curry leaves and fry a little
Add turmeric powder, asafoetida and saute them for 20sec
Add chopped tomatoes and saute them for 2~3min
Pour the ground tomato juice add salt, sambar powder and red chili powder
Allow the mix to boil, stir intermittently
Add jaggery when the tomato becomes thick pulp and mix well until they dissolves
Add rest of oil little by little and mix them well
The oil will be absorbed by the thokku [you may stop adding oil once the thokku stops absorbing the oil]
Serve with curd rice or dosa or idly