On the southern reaches of the Line 4 subway is Ansan station. This area has the best (reasonably) authentic and very affordable Thai, Cambodian, Indian and (not Southeast Asian) Russian / Ukrainian food to be found here.
There are a lot of low-income immigrants in the area, and because of this, the food has remained mostly true to the original recipes without Koreanization, since it's mostly the immigrants themselves that eat it.
It's a bit of a trek, but for anyone who's been trying to find some good foreign food, it's worth the trip. All the restaurants are fairly obvious and close to the station, as well.
