Remove the ends of the cucumber. Place one cucumber at a time on the chopping board and wack it a few times to smash it.
Cut them into thirds and then chop into about bite size pieces.
Place the smashed and chopped cucumber in a bowl and add red chili flakes, sugar, sesame oil, minced garlic and salt. Mix well.
Taste and adjust the seasoning. Serve right away or chill until ready to serve.