Using a sharp knife or mandoline, slice the cucumbers into 1/4-inch pieces, transfer to a bowl.
Add the peanuts.
In a small bowl, whisk together the vinegar, sesame oil, soy sauce, garlic, and sugar.
Add the dressing to the cucumber slices and peanuts and toss to combine. Add a sprinkling of crushed red pepper flakes to taste and serve.
Notes
TO STORE. This salad tastes best the day it is made but can be refrigerated for up to 3 days. Taste and season the leftovers with a little extra soy sauce as needed.
TO FREEZE. I do not recommend freezing cucumbers. Their high moisture content will cause them to become mushy when thawed.
*INGREDIENTNOTE: You also can swap 2 medium/large English cucumbers. Before slicing, cut the English cucumbers in half lengthwise, then with a small spoon, scrape out the seeds.
Recipe reprinted with permission from The Secret Ingredient Cookbook by Kelly Senyei. The original recipe calls for 2 Persian cucumbers, but I am a fan of the higher veggie ratio, so I added extra. Feel free to adjust to your taste.