The original recipe calls for watercress, shiso (perilla)(10 leaves) and boiled tako (octopus)--about 1 leg. The dressing is just lemon juice and some oil.
The day I wanted to make this, the supermarket had no watercress, so I subbed it with rocket/arugula. For the dressing, I used the bi bim kook soo sauce. Cut and toss.
Doesn't look as nice as the first photo, but sure does taste better.