Peel and clean the sweet potato. And then grate it.
Heat a tsp of oil in a frying pan. Add in red chili and urad dal.
Fry until dal turns slightly brown. Add in a big pinch of asafoetida and give a quick mix.
Add in grated sweet potato, and fry for 1 - 2 minutes. You can use either raw sweet potato or fry it for a while.
Add in grated coconut, give a quick mix and switch off the stove.
Add in salt, tamarind and jaggery.
Transfer it into a mixie jar.
Grind it into a smooth paste by adding required water.
Temper it with oil, red chili, curry leaves, asafoetida and mustard seeds. Serve it with dosa or idli.