Heat the vegetable oil in a large skillet over medium-high heat. Add the ground pork and cook, breaking it apart with a spoon, for 5 to 6 minutes, until no pink remains.

Add the coleslaw mix, garlic and ginger to the skillet. Cook for 3 to 4 minutes, stirring often, until the cabbage wilts and shrinks by about half.

Stir in the scallions, soy sauce, sesame oil and black pepper. Cook 1 more minute, then remove from the heat and let the filling cool for 10 minutes; it should feel warm, not hot, to the touch.

Lay one egg roll wrapper on a clean surface in a diamond shape, with one corner pointing toward you. Spoon 1/4 cup of the pork filling onto the lower third of the wrapper.

Fold the bottom corner up and over the filling, tucking it snugly underneath. Fold in the two side corners like an envelope, then roll it up and away from you into a tight log.

Brush the top corner with the egg wash and press to seal. Repeat with the remaining wrappers, keeping unused ones under a damp paper towel so they do not dry out and crack.

For the air fryer: preheat to 380°F for 5 minutes. Arrange the egg rolls seam side down in a single layer with space between them, spray lightly with oil, and air fry 8 minutes. Flip and cook 4 to 6 minutes more, until deep golden and blistered.

To bake instead: arrange seam side down on a parchment-lined baking sheet, brush all over with oil, and bake at 425°F for 15 to 18 minutes, flipping once, until golden and crackling when tapped.

While the egg rolls cook, whisk the vinegar, sugar, ketchup and soy sauce in a small saucepan over medium heat. Bring to a simmer, stir in the cornstarch slurry, and cook 1 minute, until the sauce coats the back of a spoon.

Let the egg rolls rest 3 minutes before cutting any in half; the inside stays hotter than the wrapper suggests. Serve with the dipping sauce alongside.