Add all the filling ingredients to a large mixing bowl, and mix until everything is evenly distributed.
Hold a gyoza wrapper in your palm and add 1 tbsp of the filling to the center. Leave a finger-width border around the edge.
Wet the edge with a small amount of water and fold the wrapper in half without letting the sides touch yet. Pinch one corner to start the pleat.
Push a small flap over your finger and press it down to make a pleat. Repeat until the gyoza is fully sealed.
Press the pleats down to secure the seams, then tap the base of the gyoza on a flat surface so that it stands up on its own. The flat base is important for crisping up in the pan.
Repeat until all the filling and wrappers are used up.
Heat a frying pan on medium and add 1 tbsp cooking oil. Once hot, arrange the gyoza in a single layer in the pan with the flat side down. Fry until the bases are golden and crispy (about 3-5 minutes).
Once browned, pour 150 ml freshly boiled water around the gyoza and place a lid on top. Cook until the liquid is almost gone and then remove the lid.
Avoid pouring hot water directly on the gyoza as this can make them soggy.
Remove the lid and continue to cook. Once the liquid is completely gone, remove the pan from the heat.
To make the dipping sauce, take a small bowl and mix 1 tsp Chinese-style chicken bouillon powder, 2 tbsp Japanese soy sauce (koikuchi shoyu), 1 tbsp rice vinegar, ½ tbsp toasted sesame oil, ½ tbsp chili bean sauce (toban djan), ½ tsp chili oil (rayu), ½ tsp sugar, 1 tsp grated ginger root, 1 tbsp finely chopped green onions and dried red chili pepper until well combined.
Transfer the gyoza to serving plates with the crispy side facing up and enjoy with your homemade dipping sauce!
Notes
Choose fattier beef. Lean ground beef dries out inside a thin gyoza wrapper where there is no sauce or broth to compensate. Aim for a cut with at least 20% fat. If lean is your only option, mix in a splash of sesame oil or lard before filling.Bouillon strength varies. My brand is 1 tsp per 200ml of liquid. If yours is more concentrated, start with ½ tsp and work up. If less concentrated, add a little more. Oversalting the dipping sauce is the most common mistake.Do not move the gyoza during frying. The crust needs 3-5 minutes of undisturbed contact with the pan to set. If you nudge them early, the forming crust tears and sticks. Once golden, the base releases naturally.Freeze uncooked, not cooked. Flash-freeze assembled gyoza on a parchment-lined tray until solid, then bag them. They cook directly from frozen, just add 1-2 extra minutes to the steam step. Cooked gyoza lose their crispy base after freezing.