Heat oil and sauté pottukadalai, tamarind, garlic, and red chillies for 3 minutes. Cool.
Transfer to a blender, add salt, and grind.
Add water and grind again to a chutney consistency.
Heat oil and temper mustard seeds, urad dal, red chilli, curry leaves, and asafoetida.
Add the tempering to the chutney and mix well.