Slice the Persian cucumbers thinly using a sharp knife or mandoline.

Sprinkle the cucumber slices with salt and let them sit in a colander for about 10 minutes to draw out moisture.

Blot the cucumber slices dry with paper towels.

In a small bowl, combine rice vinegar and sugar, microwave for 30 seconds, and stir until sugar dissolves.

In a large mixing bowl, combine drained cucumber slices, sliced red onions, and fresh cilantro.

Pour the dressing over the cucumber mixture and gently toss until well coated.

Cover and chill in the refrigerator for at least 20 minutes.

Before serving, sprinkle chopped peanuts over the top.