Roll filling into tight 1″ balls, placing one in the middle of each wrapper.
Use a finger/pastry brush dipped in water to moisten the edges of each wrapper. Fold the wrapper over the filling, creating a half circle. As you do this, try to push out as much of the air from the inside as possible – excess air can cause them to burst.
If you have a dumpling press, use it to seal and crimp the edges, or pleat the edges like this:
If you don’t have a dumpling press, you can fold and crimp the edges freehand. (It’s fussy though!)
Heat up 2 Tbsp vegetable, olive, or sesame oil in a frying pan – I prefer to use nonstick for this – and arrange a single layer of gyoza in the pan – not touching each other, frill side facing up. Cook until bottom side is nicely browned.
Alternatively: If you like your gyoza extra crispy, arrange them on their sides in the pan. Cook until the first side is nicely browned, flip and brown the other side before proceeding.
Once the bottom is browned to your liking, pour 1/3 cup of warm water into the pan, and quickly cover with a lid. Cook for 2-3 minutes without removing the lid.
After 2-3 minutes, remove the lid and allow Gyoza to continue cooking until all of the water has cooked off. Repeat in batches, as necessary.
Serve hot, with Gyoza sauce