Peel siru kizhangu and cut them. Wash them well. Now take them in a sauce pan, cover with fresh water. Add turmeric powder and salt. Bring it to boil and simmer till the potatoes is cooked. Drain and set aside.
Heat oil in a kadai. Add in mustard, urad dal, dry red chilli and asafoetida. Saute for 20 sec.
Add in cooked siru kizhangu and toss well in the oil.
Cover and cook for a while till the potatoes are well cooked.
Add in salt and mix well. Cook on a medium heat tossing often till the siru kizhangu is crisped a little.