Slice the Persian cucumbers into ½-inch thick rounds. Place the cucumber slices in a large bowl and sprinkle them generously with kosher salt. Toss to ensure they are evenly coated. Allow to sit for 30 minutes in the refrigerator.

In a separate bowl, whisk together rice vinegar, mirin, sugar, sesame oil, minced garlic, and a pinch of salt until smooth. Set aside as cucumbers marinate.

Rinse the cucumbers in a colander under cold water to remove excess salt and pat them dry with paper towels.

Transfer the rinsed cucumbers to a clean bowl and pour the dressing over them. Toss gently to coat. Cover and refrigerate for at least 4 hours.

Taste the salad before serving and adjust seasoning if necessary. Drizzle extra chili oil and sprinkle freshly minced Fresno chile pepper. Serve chilled.