I think what you are looking for is 감자채
채 means thin long slices of a vegetable, so it's 감자채 instead of 무채
How to make it is simple :
You need potato, soy bean sauce, salt, cooking oil.
Slice up the potato, and wash it once again and drain all the water out of it,
and then fry it in a little bit of cooking oil over moderate fire
And after a while you start adding soy bean sauce and salt, little by little,
until you get the taste you want.
You can add onion or piman if you'd like to.
If you give it a try, let me know how it went!