Begin by blanching the napa cabbage in boiling water for 30 seconds. Drain the cabbage in a colander and rinse with cold water. Squeeze any excess water from the cabbage with your hands.
To the food processor, add the blanched cabbage, ground pork, smashed garlic, ginger, scallion, 2 tablespoons vegetable oil, sesame oil, soy sauce, sugar, salt and pepper. Pulse the mixture in the food processor until the filling is well-combined.
Prepare sheet pans or cookie sheets lined with plastic wrap or parchment paper. To assemble the gyoza, place about 2 teaspoons of filling in the middle of each wrapper, and use your finger dipped in a small bowl of fresh water to moisten the outer edges of the wrapper. You could simply fold them in half, or you can pleat them as you see in the photos. Make sure they are well-sealed.
Heat a tablespoon of cooking oil in a nonstick or cast iron skillet over medium high heat. Place the gyoza in the pan and fry until the bottom of the gyoza become crispy and golden, about 2-3 minutes.
When the gyoza have fried, add 1 tablespoon of water to the hot pan and immediately cover the pan to steam the dumplings. Let the gyoza to steam until the water has evaporated (about 2 minutes), remove the cover, and continue cooking until the bottoms of the gyoza get crispy again.
Prepare your dipping sauce by combining all the sauce ingredients in a small bowl, and serve alongside the crispy gyoza!