A lot of people go to restaurants and see that there are curled shredded scallion on the top of the soup or dish. You should not think that the scallion is cut very thin. In fact, there are some ways to do it
1. Cut the scallion into 2-3cm segments
2. Cut it vertically. The thinner the silk, the easier it is to roll
3. Soak the cut scallion shreds in water for a while and then roll into a roll.