Grilled fish (mostly mackerel, 고등어) is a very popular dish in Korea. It is popular so many restaurants have it as an option, especially in the touristy area of Seoul. However, one thing to note about Korean restaurants in Korea is that most authentic and good ones are very specialized. They don’t usually have a menu composed of all kinds of different foods, but specialize in a single topic. So if you want to find the best grilled fish, you go to a restaurant where the primary topic of their menu is grilled fish related items. Also, there is usually a spot where many restaurants all congregate and specialize in grilled fish. It is strange how that works since you’d think grilled fish restaurants would open far away from each other, but for some reason, many of these places are right near each other.
One such well-known grilled fish place in Seoul is Honam Jip (호남집). It is near Dongdaemun (동대문, east gate) at the busy marketplace there (specifically, Dongdaemun subway station stop exit 8). Be prepared for one of the best tasting mackerel (with rice and accompaniments of course). Do not worry if your partner is a vegetarian and/or not into fish. There are other things on the menu, but if you don’t taste the grilled fish, you are missing out.