Wash the cucumbers and cut them into quarters lengthwise. Sprinkle salt over the cucumbers and let them sit for about 30 minutes to draw out moisture.

In a mixing bowl, combine Korean red pepper flakes, minced garlic, grated ginger, fish sauce, and sugar. Mix well to form a paste.

After 30 minutes, rinse the cucumbers under cold water and drain. Add the cucumbers to the kimchi paste and mix until well coated.

Transfer the cucumber mixture to a clean jar, pressing down to remove air bubbles. Seal the jar and let it sit at room temperature for 1-2 days to ferment, then refrigerate.

Serve chilled, garnished with sliced scallions.