Finely chop coriander and green onions and combine in a bowl. Sprinkle on potato starch.
In another bowl, combine ground pork, fish sauce, sugar and sesame oil and mix well. Add in chopped coriander and green onions and mix to combine.
Place perilla leaf onto a gyoza wrapper. Place a small spoonful of the meat mixture on top and roll it up. Secure by pressing the edges together with a little water. Repeat until all ingredients are used up.
Grease the bottom of a frying pan with some oil and arrange the dumplings on top.
Turn on the heat and cook until you can hear a crackling sound.
Add in a little hot water. Cover and cook over medium heat for 10 minutes.
Take the lid off and cook uncovered until the bottom of the dumplings are crispy and golden brown.