Well, I don't know about Korean people, but I tried stir frying a few and they tasted like toasted grass -- very stringy and fibrous. I don't think it's for me. I am cooking some leaves up now, though. I love them boiled as pot greens. Yum! The stems, however, are going into the compost pile.

ETA: I read the recipe again, and it seems you are supposed to peel the stems. Who has time to do that? i peeled one and chomped it raw, and it still is too stringy and fibrous.