A few days in Seoul is a short time to do everything you want to do, particularly when you're competing with your wife in trying to compare the relative merit of visiting your second temple of the day vs. your third fried chicken joint of the day. (Clearly, the latter should take precedence, right? Seen one temple, you've seen'em all.)
But finding good food is not a difficult task. Korean food is simpler and homier than, say, Japanese food, though the two cuisines do share some characteristics—the combination of sweet and savory flavors, plenty of seafood, and lots of grilled and simmered dishes.
One major theme you'll find in Korean cuisine is the prolific use of kochukaru (chili powder), fermented soybean paste (similar to Japanese miso), and gochujang (a sweet chili paste), though it's important to remember that while the bright red color of many dishes might make them appear to be spicy, Korean chili is actually relatively mild—it's more about flavor than outright heat.
About the author: J. Kenji Lopez-Alt is the Managing Editor of Serious Eats where he likes to explore the science of home cooking in his weekly column The Food Lab. You can follow him at @thefoodlab on Twitter, or at The Food Lab on Facebook.