I started everyday the same way - with food I brought from home and enjoyed in my hotel room. I bought coffee drinks, milk and fruit at the corner market.
I also tried traditional Korean food - an egg pancake with green onions and octopus, along with a variety of kimchi.
I consumed a ton of coffee drinks in Korea. There are all sorts of canned, boxed and bagged coffee drinks available at convenience stores, both hot or cold. They all rock.
One of my favorite meals was at a restaurant in my hotel called the Yellow Ribbon. It was a pretzel and pizza place that also had rocking drinks. During the course of my trip, I had a Blue Hawaii drink, which was a delicious combo of tropical flavors. I also had a coconut cafe latte and a sweet potato pizza on separate occasions. The pizza was awesome - a base of mashed sweet potato puree replaced the sauce over a super-thin crust. Yum. Everyone I traveled with ate there at least once.
One ingredient that's big in South Korea is red bean paste. It's frequently served in desserts, and I tried them in a baked pancake type pastry from the market at the Haedong Yonggung Temple. I had another pastry with red bean paste at a bakery near Haeundae Beach. It had both mascarpone and the paste inside, so I'm sure it was super healthy ... I liked these desserts because they weren't too sweet.
A more authentic dish that I enjoyed was ice flakes. It's a traditional dessert in South Korea that features a snow-cone like layer of shaved ice topped with a variety of flavors. I tried it twice. The first time, I had a milk tea-flavored ice flakes dessert from a Twosome Place, a chain that's everywhere in South Korea and got tons of my currency for coffee and lunch. It was topped with granola and yogurt ice cream and was amazing. I loved the creaminess of the ice cream along with the crunch of the granola and ice chips.
The second place I tried the dessert was at Lapland Cafe and I didn't like it as much. However, it might have been my own fault. The menu didn't have pictures or English translations, so I had no idea how to order. I ended up with a bowl of ice flakes topped with gelato, some chewy candy type thing and what looked like lemon curd. It was good, but I didn't like the texture of the ice flakes as much.