Step 1

Stir black vinegar, ¼ cup soy sauce, ½ tsp. sugar, and ½ tsp. gochugaru in a small bowl until sugar is dissolved; set dipping sauce aside.

Step 2

Drain kimchi in a strainer set over a medium bowl in the sink. Wearing gloves, squeeze all juice out of kimchi; reserve kimchi juice for another use (it’s great in soups!). Chop kimchi and set aside (you should have about 1½ cups).

Step 3

Using clean hands, mix pork, scallions, garlic, ginger, broth, sesame oil, oyster sauce, salt, white pepper, remaining 2 Tbsp. soy sauce, remaining 2 tsp. sugar, and remaining 1 tsp. gochugaru in a large bowl until well combined. Switch to a wooden spoon and mix, stirring in one direction, until a thin white film forms on the sides of bowl, about 4 minutes (this ensures the filling will hold together when spooned into wrappers and also doubles as your arm day workout.) (Alternatively, mix filling in a stand mixer fitted with the paddle attachment on low speed until a film forms on the sides of bowl.) Mix in reserved kimchi. Chill filling while you set up your dumpling wrapping station.

Step 4

Line 2 rimmed baking sheets with parchment paper. Set wrappers on a small plate and loosely cover with a damp paper towel to prevent them from drying out while you are folding dumpings. Place a small bowl of water near your work surface.

Step 5

You’re ready to wrap! Lay a wrapper flat in the palm of your nondominant hand. Spoon a heaping teaspoonful of filling into center of wrapper. Dip a finger of your dominant hand into bowl with water and moisten the half of wrapper nearest to you. Bring moistened wrapper half together with dry half to form a semicircle and pinch middle to seal. Working from one corner toward the middle, create 1 or 2 pleats along one edge of dumpling; repeat working from the opposite corner. Place dumpling on a prepared baking sheet so the pleated side is facing up and the dumpling has a flat bottom (this is the side that’s going to get maximum crisp!). Cover with a damp kitchen towel or a sheet of plastic wrap and repeat process with remaining wrappers and filling.

Step 6

Pour 1 Tbsp. vegetable oil into a cold large nonstick skillet with a lid and swirl to coat bottom of pan. Arrange half of dumplings, flat side down, in a single layer in skillet, then carefully pour in enough water to cover bottom third of dumplings (about ½ cup). Cover skillet, place over medium-high heat, and bring to a simmer. Reduce heat to medium and simmer dumplings until water is almost completely absorbed, about 5 minutes. Uncover and cook until skillet is dry and bottoms of dumplings are deep golden brown and crisp, about 3 minutes. Transfer dumplings to a platter. Swirl remaining 1 Tbsp. vegetable oil into skillet and repeat cooking process with remaining dumplings (or freeze the rest for a rainy-day snack).

Step 7

Serve dumplings hot with reserved dipping sauce alongside.Do Ahead: Filling can be made 1 day ahead; cover and chill. Dumplings can be formed 2 months ahead; freeze in a single layer on a baking sheet until solid, then transfer to a resealable plastic bag. Cook dumplings from frozen as directed above.