1. Generally, they are sold in supermarkets. Some of them are made by supermarkets and some are made by bread companies. The general name is special bread embryo for hamburgers or something similar, which is specially used to make hamburgers.

2. Go to the shopping mall and buy the Jiadun bread with sesame seeds on it. When you come back, cut it in the middle, butter the cut side, fry it in a pan, pick it up and put it in the middle of the bread.