firstly, wash, peel and chop / grate the sweet potatoes well.
in a frying pan add 1 tsp of oil. roast 2 tsp of urad dal, 3-4 kashmiri dry red chilies, few curry leaves and asafoetida on medium heat.
fry until the urad dal turns golden brown. allow them to cool.
in a blender add 4 tbsp of grated fresh coconut, small lemon size tamarind, salt and grated sweet potatoes. ground them to smooth paste.
make sure to add small amounts of water to bring it to the right consistency (thick dropping consistency).
prepare tempering by heating 2 teaspoons of oil in a small pan. add mustard seeds, curry leaves. red chilli and allow them to splutter. add asafoetida (hing).
turn off the heat. transfer the tempering to the chutney.
serve sweet potato chutney with roti/chapati/rice/ dosa or as an accompaniment.