Wash cucumbers thoroughly under cold water. Slice into 1/4-inch rounds, aiming for around two cups.

Combine sliced cucumbers and minced garlic in a large jar or mixing bowl.

In a separate bowl, whisk together soy sauce, sesame oil, rice vinegar, chili flakes, sugar, and salt until sugar is dissolved.

Pour dressing over cucumber and garlic mixture, ensuring all slices are evenly coated.

Seal jar or cover bowl and shake or stir for 30 to 60 seconds until well combined.

Let cucumbers rest for 5 to 10 minutes at room temperature.

Transfer to a serving bowl and garnish with sesame seeds and green onions as desired.