
The trick to any sliced cucumber salad is to slice the cucumbers as thin as you can and to purge them by salting them before making the salad so the dressing doesn’t get watered down by the cucumber juice.
Sprinkle the cucumbers with a generous amount of salt and let sit in a colander in the sink for 15 minutes. Rinse and dry on a kitchen towel. Transfer to a salad bowl.
Whisk together the vinegar, soy sauce, sugar, garlic, ginger, cayenne, and pepper. Whisk in the sesame oil and the sunflower or grapeseed oil. Toss with the cucumbers, scallions, and cilantro. Chill until ready to serve.