This is a pretty well-known cheap eats Chinese food chain in Korea.
I have been to locations in Gangnam, Sillim, Seoul National University, Korea University, Konguk University...etc.
It is pretty well-known for its jjambbong (짬뽕) (Korean-Chinese spicy seafood soup). I, unfortunately, do not have a picture of it, but it looks like jjambbong typically does, red broth with mussels, clams, and noodles. Their version is actually pretty spicy. You can get a regular size for 4000KRW (about 4USD) otherwise you can get a larger size for 5500KRW (about 5.50USD).
If you're not really feeling the soup, you can get jjambbong bap (짬뽕밥), which is served with rice in it instead of noodles for 4500KRW (about 4.50USD). You can get fried jjambbong (볶음짬뽕 - bokkeum jjambong) for 5500 KRW (about 5.50USD).
What jjambbong jip would be complete without serving tangsuyuk (탕수육 - sweet and sour pork)? It can be had here for 8000KRW for a small size and 15000KRW for a large size.
They also sell fried mandu (군만두 dumplings). You can get a full plate for 4000KRW or a half plate for 2000KRW.
They also have jjajjangmyun (black bean noodles). 4000KRW for a small size and 5000KRW for a large size.
What I ate was a summer special dish. It was a ridiculously hot summer day in Seoul. It is called chagamyun (차가면) and is 5000KRW. It is served cold and is not spicy. The noodles are served alongside the toppings (seen to the left).
During summer, they also serve a cold jjambbong (냉짬뽕).
There are locations all of over Seoul and locations in the United States.
If you want me to let you know where the nearest location to you is, just leave a comment.