Separate scallion greens and whites. Reserve the white ends for another recipe. Fill a mixing bowl with ice and water.
Cut the greens into 2–3 inch sections. Slice each segment in half lengthwise. Stack 2 or 3 pieces at a time and slice lengthwise into thin strips.
Transfer scallion greens to the ice bath and submerge. Leave for at least 5 minutes, or until they start to curl. Remove from the ice bath and gently pat dry with a paper towel.