If you decide to grind your own pork shoulder (butt) for the recipe you can do that up to 1 day in advance. First, cut and partially freeze the pork in 1-1 1/2in (2.5-3.8cm) slabs for about 1-2 hours. From there, cube the pork into 1/2in (1.3cm) squares. Place a bowl under your grinder and run the partially frozen cubes through it, using the finest grind plate you have. Cover the bowl when done and store it in the refrigerator until you are ready to mix the filling.
If you want to make your wrappers from scratch, begin the dough about 1 hour before you make the gyoza. This recipe is for a hot-water dough. (see notes for other options and characteristics) Measure out the flour and salt and and add just the flour to a medium bowl or stand mixer bowl. Next, measure out 1/4 cup tap temperature water and set aside. Then, add water to a small pot. Bring that water to a boil on your stove top. As soon as the water boils, remove the pot and pour 1/2 cup of the water into a measuring cup. Add in the salt and use a small whisk or fork to dissolve the salt.
Now, turn on the mixer or use that same fork (or chopstick) and slowly pour the salt water into the flour mixing as you go. Once all of the hot water is in, mix until the dough gets shaggy (about 30-60 seconds) and then stream in the separate cool water. You may not use all of it. You want the dough to be tacky and malleable, but none of it should stick to your fingers. Mix until a dough ball forms and all of the flour has incorporated (another 1-2 minutes in the mixer and 2-5 minutes by hand).
Stop mixing and let the dough rest for 15 minutes. Then, mix again for 1-2 minutes until the dough is smooth and has just a little bit of spring back when you push your thumb into it. At this point, the dough is ready to rest in the refrigerator until it’s time to roll out your wrappers. Hot water doughs need less rest time, so you can begin the filling immediately.
For the filling, slice the napa cabbage into 1/4in (.6cm) wide slices. If you get past the top of the cabbage before you hit the amount you need, start pulling off the leaves and stack them so you can cut around the center vein that connects to the core of the cabbage. Rinse the strips and run them through a salad spinner to make sure they are clean and relatively dry. Take the strips and chop them down further into finely-minced pieces.
From there, put your cabbage into a bowl, colander with small holes, or large fine-mesh strainer and mix with 1/2 teaspoon (2.4g) kosher salt. Set aside in your sink to let the cabbage rest and drain for 15-20 minutes.
While that is happening, take the bowl of ground pork out of the refrigerator and set it aside. Grate the ginger into a separate small bowl and add in the soy sauce, sesame oil, roasted garlic, cornstarch, and salt. Then, finely chop your garlic chives and dump them on top of the pork. Don’t mix yet. Almost there, I promise.
Now, squeeze out as much moisture from the cabbage as you can. You can use a cheesecloth or your hands, depending on what you prefer/have on hand. You should have about 3/4 cup (95g) of cabbage after squeezing. Dump that into the pork bowl as well as the seasoning slurry.
Now, you can mix by hand to make sure everything is well incorporated. (If you hate touching your food, you can use a spatula. It will just take a bit longer.) Cover the filling and set it in the fridge while you make the wrappers. (if you have store bought wrappers, skip this next step and start shaping your dumplings)
For the wrappers, first, setup your work space. I prefer to use the pasta attachment for my stand mixer (see FAQs for rolling out wrappers by hand) to roll out the dough. Keep some flour and cornstarch on hand to dust both the dough and your surface when working. You will also need a kitchen scale, 3.5in (9cm) round cutter, #50 cookie scoop, and a silpat covered baking sheet.
It’s important not to expose your wrapper dough to the air too much or it will dry out. To avoid this, cut off a 50-55g piece of dough (about 1/8th the total dough ball) to roll out one-at-a-time and leave the rest wrapped. Flatten the piece to about 1/2 in (1.3cm) and then send it through the pasta roller on setting #1. Each pass through, turn the dial one higher, until you have it to #6. Feel free to send the dough through more than once on a single setting to ensure even thickness. The dough should stretch to between 20-22.5in (50-57cm). From here, cut out 5 wrappers with your cutter and retrieve the filling from the refrigerator.
Now, use a #50 cookie scoop to portion out 1tbsp (20-22g) of filling onto a wrapper. Shape the filling a bit, so it’s oblong and not a circle.
Leave the dumpling resting on the table and fold the front and back sides up to meet in the middle. Pinch the very center and then pleat the left and right sides. To form a pleat, you will essentially use three fingers: an inside index finger that forms a pocket and pushes under to begin a pleat and an outside index finger to help pull the pleat over the first index finger and pinch. Once a fold is made, seal it by removing the inside index finger and pinching it to the other side of the wrapper using your outside index finger and thumb. Keeping the dumpling stationary ensures you only make pleats on one side to create the signature crescent shape.
Place each gyoza onto the silpat for later. Once 5 are made, repeat the rolling, cutting, and shaping process until all the filling is gone. It is likely you will have leftover dough.
At this point you can place the tray in your freezer. Once frozen, simply transfer the dumplings to a plastic bag and freeze for 2 months. you can cook them directly from frozen.
If you want to cook the pork gyoza, either fresh or frozen, place a small (8-10in / 20-25cm) non-stick pan (that has an accompanying lid) on your stovetop and turn the burner to medium-high. Add in about a tablespoon of a neutral oil, like vegetable or canola. Once the oil heats up, add between 8-10 gyoza to the pan. It’s best to arrange them in a pinwheel shape to fit more. Let the gyoza bottoms cook until they are crispy and brown on the bottom. About 3-5 minutes depending on the heat.
At this point, pour roughly 2-3 tablespoons of water into the pan and immediately cover it. Turn the heat down to medium-low and let the gyoza cook until they are 160°F or 71°C internally. This takes another 3-7 minutes depending on if they are fresh or frozen. Once they have steamed through, take the lid off and turn the heat up once more. Let the bottoms of the gyoza re-crisp and then turn them onto a plate when done to enjoy.
If you’d like a dipping sauce for your dumplings here’s one to make at any point before or during the process. First, collect all of the ingredients. Chop up the scallions and add them to a small bowl. Follow the scallions with sliced garlic and ginger, sesame seeds, and chili flakes. Add the sesame oil to a pan and turn on the heat to medium-high. Let the oil heat until you just start to see wisps of smoke. Remove the pan from the heat and immediately pour the oil into the bowl of spices. They should bubble from the hot oil. At this point you can add the soy sauce and shaoxing wine.