Slice the cucumbers into ¼-inch rounds, sprinkle with salt, and let them sit for 10–15 minutes.

Rinse the cucumbers under cold water 2–3 times to remove excess salt and drain thoroughly.

Combine fish sauce, sugar, minced garlic, and Korean red pepper flakes in a bowl and whisk until blended.

Add drained cucumber slices, julienned carrots, and optional Asian chives to the marinade, tossing gently to coat.

Transfer to a serving dish and garnish with sesame seeds. Chill for 30 minutes before serving.