Directions :

1. In a medium bowl, whisk together hot water and sugar until the sugar is dissolved. Whisk in soy sauce, rice vinegar, ginger, sesame oil, Sriracha, and garlic. Add red chili flakes to taste (I like ½ teaspoon) and set aside.
2. In a large bowl, add pork, cabbage, mushrooms, scallions, soy sauce, cornstarch, ginger, sesame oil, mirin, garlic, ½ teaspoon salt, and ¼ teaspoon pepper. Mix well to combine (I like to use my hands while wearing gloves, but a sturdy spatula works too). You will have about 3 cups of filling.
3. To test the seasonings in your filling (and important step to be sure it is properly seasoned), scoop a teaspoon-sized ball of filling, flatten into a patty, and fry in a dry skillet until browned, about 2 minutes per side. Taste and add more salt and pepper if desired (I usually add another ½ teaspoon salt and ¼ teaspoon pepper, or 1 teaspoon salt and ½ teaspoon pepper total). Fry a second teaspoon of filling if you want to double-check your seasonings.
4. On a clean work surface, arrange 8 wonton wrappers (keep remaining wrappers covered with a damp kitchen towel or paper towel to prevent them from drying out). Brush the edges of each wonton wrapper with water.
5. Place 1 tablespoon filling in the center of the wrapper (I like to use the OXO small scoop, a #70 portion scoop). Fold the wrapper in half to enclose the filling, and pleat the outer edge, pressing damp edges together firmly. Transfer to a plate under the damp kitchen towel while preparing the rest of the potstickers.
6. In a large nonstick frying pan over medium-high heat, heat 1 tablespoon oil until shimmering. Add 12 pot stickers, flat bottom down and in a single layer. Sear until golden brown on the bottom, 2 to 3 minutes.
7. Pour ¼ cup broth in the pan, cover, and let steam until all the broth evaporates, the pot stickers are tender but still firm, and the filling is cooked through, 3 to 4 minutes. Cook the remaining pot stickers and broth in three more batches. Serve with the ginger sauce.