What foods do they eat in South Korea?

it's a Kimchi

South Korean food is well known for the variety of tastes and textures presented in any single meal. Many different meats, fish, vegetables, rice, noodles, soups and side dishes (especially the renowned spicy and fermented kimchi) are served at any meal. These are prepared in a myriad of ways. A meal is not complete without soju, beer or wines.