Trim the ends of the cucumbers. Starting at one end of a cucumber, place the flat of your knife (or a rolling pin) on top of the cucumber. Gently but firmly strike the blade with the heel of your palm to smash the cucumber (“so the vegetable splinters and opens up with jagged cracks” or “so it splits”). Cut into bite-sized pieces, and set aside in a medium bowl. Repeat this for the rest of the cucumbers. If there are any large sections, you can cut through them.
Add the soy sauce, vinegar, sugar, garlic, and red pepper flakes to the medium bowl and mix well. Cover and let the cucumbers marinate on the counter for at least 30 minutes before serving. Store the cucumber in the refrigerator, covered, for up to 3 days.
Hsiao-Ching Chou is the author of "Chinese Soul Food: A Friendly Guide for Homemade Dumplings, Stir-Fries, Soups and More." She lives in Seattle with her family. Text her cooking questions via her messaging service: 206-565-0033.