Korea has so many people and yet it is so small. So it really shouldn't come as a surprise that much of the food from one end of the country to another is basically the same.
By far, one of joys of living in Korea is the food. One of the staple places to get food is from a tok-bo-ki stand.
These stands never fail to amaze me for a variety of reasons. First, there are so many of them. Yet, they all serve basically the same food. This makes them more common than Starbucks in Seattle (barely)!
In the picture you can see 5 stands. Every day, these carts (or sometimes the back of small pickup trucks) move out along the street corner and hawk their wares. At the end of the night, they close up, pack up, and move their restaurant away to do it all over again the next day.
While their is some variety to what they sell from booth to booth...almost all of them have 2 dishes in common. The first is fish paste on a stick. The fish paste (called u-dang) cut into long, strips, skewered like a kabab, and boiled. The broth is later served with onions and pepper as a kind soup.
The other common dish is staple of Korean life called ttok- boki. The ttok is actually just rice cake. When served in ttok-boki, it is served in pieces that size of water chestnuts slices, or maybe sections the size of rigatoni. Sometimes Koreans will make ttok into just that...cakes. It will come in sections the same size as a cake pan. It will be loaded with various nuts, corn, and onions. But that's not their favorite way to enjoy it!
What gives it the name boki is the sauce. At the base of the sause is the chili paste called go-chu-jang. This red, spicy paste is a common as ketchup in Korea. With most Korean meals, there will be wide variety dishes...and always a side of go-chu-jang
The spice is a bit too spicy for most Koreans taste (mine too for that matter) to be eaten in bulk. Instead, they cut it with another less spicy sauce you may have heard of called "ketchup." Once the two are combined in the proper ratio, they are heated with u-dang (that pesky fish paste again) and served. This is basically what you find on every street corner in Korea.
As with all common dishes, there is room for improvements. In fact, most Koreans believe that they have a secret, family recipe. Think like Americans and their chocolate chip cookie recipes. The one time I've been fortunate enough to watch the cooking process. She added onions, tini-weenies, carrots, and cheese. It was ok...but nothing to write home about.
But back to street vendors...other things you may find include deep fried vegetables, mandu (think won-tons) filled with either meat or kimchi (spicy sauerkraut) and various types of meat kababs (chicken or some form of sausage with or without spice)
But they all have ttoki-boki. And by far, whenever I ask my kids what their favorite food is...they always mentoin ttok-boki.