Winter bread(Ho-bbang) is made after fermenting the dough, steamed in a warmer filled with vegetables,ground meat, red bean.
Fits well in a country where has cold weather.
So, popular in Korea throughout the winter months sold at convenience stores.
It is pre-cooked and be in a warmer for sale and outlet stores sell in a bulk.
Can be easily heated in a microwave or an electric rice-cooker at home.