To pan-fry or chien banh chung, you will need to re-heat the sticky rice cake so that it is soft. Then heat 1-2 tablespoons of oil on medium-high on a large skillet and press the banh chung onto the skillet with the potato masher. Keep pressing until it is an even layer. Pan-fry it on one side until it is golden brown then flip it with a spatula and cook it on the other side until golden brown.