The opposite of Korean food is Middle Eastern food
Ok the title is not entirely true, but humor me. So I have this pet theory. When I was eating in South Korea, I found myself missing Middle Eastern food a lot. Good warm pita. Baba ganoush with olive oil and pine nuts on top. Spiced lamb. Chicken on skewers. I craved a savoriness that could not be satiated. So my idea is that you can figure out the opposite of a culture's cuisine by only eating that for a week. What you crave is the opposite.
This assumes that a culture's cuisine isn't varied, but I think it's a fun thought experiment.
No, but seriously. The first thing I did when I came back to the US was devour an entire chicken schwarma.