6 Persian cucumbers (about 1 pound), cut lengthwise into thin spears, then cut crosswise into 2-inch pieces
1/4 cup salted, roasted peanuts
1/4 cup cilantro leaves
1 teaspoon red-pepper flakes
3 tablespoons natural unsalted peanut butter
2 tablespoons soy sauce
2 tablespoons unseasoned rice vinegar
1 teaspoon granulated sugar
1 small garlic clove, grated
Chile oil, store-bought or homemade, for serving (optional)
Toss cucumbers with 1/2 teaspoon kosher salt in a colander. Set aside to drain.
Chop peanuts, cilantro and red-pepper flakes together until very fine. Set aside.
In a large bowl, whisk together peanut butter, soy sauce, rice vinegar, sugar, garlic and 1/2 teaspoon kosher salt. Add up to 1 tablespoon water, if needed to thin mixture. Transfer salted cucumbers to the bowl with dressing and toss to coat.