This is a restaurant I never would have found without Happy Cow, and I'm glad I did. It's located well outside of town, but it's not far from Lake Bomun where we were staying. You'll almost certainly need to take a taxi to get there, but the taxis are relatively cheap and the food is well worth the trip. While not completely obvious from the front, the restaurant is downstairs and around the back. The decor is quite cute -- some of our party described it as being inside a doll house -- and the overall ambience is very relaxing. The staff were a bit shy, but very friendly. One of them (the owner, I believe) even gave us a ride back to our hotel when they had trouble getting a taxi for us.
The entire menu is vegan, and their is a lot too choose from. The mushroom soup was excellent, as was the vegetable platter. I tried the brown vegetable fried rice and the seitan bulgogi, both of which were very good. Others had the mushroom steak (mushrooms are a local specialty), and the whole wheat pasta. Everyone was happy with their choice. In fact, we liked it so much that we returned the next day for an encore.
Cons: A bit out of the way