Cheongpomuk (mung bean jelly)
The name translates as "clear froth jelly," which sounds like something you should be paid handsomely for putting in your mouth. But it's actually just mung bean starch, and it does pretty much what lemon sorbet does during a fancy French feast: cleanses the palate. Garnished with a little sesame oil and/or soy sauce, maybe a little chile and scallion, it's one part flavor to three parts texture. (Muk made from acorn starch is also common, though wiggling cubes of liver-brown gelatin take a little getting used to, which in turn takes a lot of soju.)
Danmuji (pickled radish)
"Show any Korean pickled yellow daikon with onion, and they'll know right off the bat" that the main course will be jajangmyeon, or Chinese-influenced black bean noodles, says Joe Kim of Dae Gee in Denver. That's how closely the two are associated. It's important to note here, however, that danmuji is just the sweet-and-sour daikon part. Onions come separate.