Finely chop the cabbage and mix with salt in a bowl. Let sit for 5 minutes. Mince the green onion and cut shiso leaves in half lengthwise.

Mix vinegar and soy sauce in a separate bowl to prepare the dipping sauce.

In another bowl, combine ground pork, minced green onion, squeezed cabbage, and the ☆ seasonings. Mix until sticky to form the filling.

Place one shiso leaf and 1/20th of the filling onto a gyoza wrapper. Wet the edges with water and fold into pleats to seal. Repeat for all wrappers.

Heat salad oil in a pan over medium heat. Arrange the gyoza and cook for 2 minutes until browned. Add 3 tbsp water, cover, and steam on low heat for 5 minutes. Remove the lid and cook on medium heat until water evaporates and gyoza are crispy.