You may or may not have heard, but every Sunday Filipinos all over Seoul get together and put on a market, selling products from the Philippines and Filipino food right in the middle of Hyehwa.
On the particular day that we visited, the Seoul Global Center had some information and health check services for Filipinos.
But, as I know nothing about the advantages of Filipino shampoo over Korean or American shampoo I focused in on the food to be had.
It seemed that most of it was fried stuff, but there are some non-fried options too.
This plate of food below cost $5,000 won all together. A lot more expencive than the Philippines I'm guessing, but still not a bad price, I think. There's some meat here, plus fried bananas, fried banana in crispy shell and... something else I don't remember.
The market opens every Sunday near Hyehwa station on line 4. Go out exit 1 and walk up to the intersection, about a 3 minute walk.