1 large bunch scallions, white and green parts only, cut into 4-inch lengths
2 tablespoons unseasoned rice vinegar
2 teaspoons sugar
1 tablespoon Asian sesame oil
1/2 teaspoon coarsely ground Korean chile (gocho karu)
Large pinch of coarse salt
Slice the scallions lengthwise into fine strips. Submerge the strips in a bowl of ice water until curled, about 1 hour. Just before serving, drain well and pat dry with paper towels. Transfer the scallions to a bowl and toss with the remaining ingredients.