At Korean lounges when you order soju or beer you also have to order some sort of a side dish.  They range from platters of fruit  to french fries or fried fish.  If it's just a drinking bar I've seen mostly just the grilled dried squid.  There are street vendors that line the streets and you can find any variety of things: fish sausage, spicey rice cakes, mandu (dumpling), other fried things.