Slice the Persian cucumbers into thin rounds and add them to a bowl. (For the craggy, sauce-grabbing version, smash them lightly and chop instead.)
Thinly slice the green onions and pile them in.
Add the Chili Onion Crunch, rice vinegar, sesame oil, and a pinch each of salt and sugar. Start with the smaller amounts.
Toss everything together until the cucumbers are well coated.
Let it sit for 5 to 10 minutes so the flavors come together and the cucumbers soak up the sauce.
Taste. If it needs more punch, add the rest of the Chili Onion Crunch (and a little more vinegar or sesame oil if you like). Serve cold.