Gently smash 500g of cucumbers with a rolling pin until they split. Cut into 1in / 2.5cm chunks. Toss with ¾ teaspoon of salt; leave for 20 minutes, then drain.
Mix 1½ tablespoons of rice vinegar, 2 teaspoons of toasted sesame oil, 1½ teaspoons of grated ginger, 2 teaspoons of soy sauce, and ½ teaspoon of sugar.
Toss the cucumbers with the dressing, 2 tablespoons of chopped cilantro and ¼ cup of sliced scallions. Serve immediately.
