Gimgane Gimbap Seongsu Sigma Valley Branch serves gimbap and Korean bunsik for a quick meal in Seongsu Sigma Valley. Gimbap makes it suitable for a simple meal, with less of a burden than other restaurants in Seongsu. The area is crowded with offices, so the restaurant is busy at lunchtime. If you tell the staff late that you will pay with Seoul Pay, they respond irritably and loudly.