Use a sharp knife to slice off the ends of the cucumbers, then peel if the skin is thick or waxed. Thinly slice the cucumbers lengthwise, creating delicate, crisp rounds or strips.
Transfer the cucumber slices into a clean mixing bowl, spreading them evenly so they’re ready for dressing.
In a small bowl, whisk together the rice vinegar, sugar, salt, and red pepper flakes until the sugar dissolves completely, releasing a fragrant, tangy aroma.
Pour the dressing over the cucumber slices, then gently toss everything together with a spoon or tongs, ensuring each slice is evenly coated and glistening with the bright, tangy dressing.
Sprinkle the chopped dill or cilantro over the salad, then give it a final gentle toss to distribute the herbs throughout, adding a herbal freshness.
Serve immediately for maximum crunch and freshness, or refrigerate for up to 2 hours if preparing ahead. The salad will remain crisp and flavorful, perfect as a refreshing side dish.