Hello!
I have compiled an extensive list of vegetarian (organic and vegan included) restaurants in Korea. It's all here:
http://www.freewebs.com/vegetariankorea/index.htm
Even if you're not veggie, you may enjoy some of these places!
If you have a Korea blog or website, PLEASE, please, find it in your heart and schedule to link my site and much good karma is bound to come your way.
Peace,
Sonia