Step 1

Place a fine-mesh strainer over a bowl. Halve 1 pound Persian cucumbers lengthwise, then cut crosswise into 1 to 1 1/2-inch pieces. Cut each piece in half diagonally.

Step 2

Place the cucumber pieces in the strainer, sprinkle with 1/2 teaspoon of the kosher salt, and toss to combine. Let sit for at least 30 minutes or up to 1 hour — the salt will draw the water out of the cucumbers. Meanwhile, prepare the wakame, dressing, scallions, and herbs.

Step 3

Place 1 tablespoon dried wakame in a medium bowl and cover with 1/4 cup water. Set aside to hydrate for at least 10 minutes. Pat dry with a paper towel, then coarsely chop. You should have about 1/4 packed cup chopped, hydrated wakame.

Step 4

Place 2 tablespoons rice vinegar, 1 tablespoon of mirin, 1/2 teaspoon hondashi or 3/4 teaspoon fish sauce, 1/2 teaspoon granulated sugar, remaining 1/2 teaspoon kosher salt, and 1/4 teaspoon red pepper flakes in a large bowl. Whisk until the sugar, hondashi, and salt are dissolved. Whisk in 1 tablespoon toasted sesame oil.

Step 5

Thinly slice 2 medium scallions, keeping the whites and greens separate. Add the scallion whites to the wakame. Place the scallion greens in a small bowl. Tear 2 tablespoons cilantro leaves and 2 tablespoons mint leaves into small pieces, add to the scallion greens, and toss to combine.

Step 6

Add the salted cucumbers, wakame, and scallion whites to the vinegar mixture and toss to combine. Let marinate, stirring occasionally, for 5 to 10 minutes.

Step 7

Taste and season with more kosher salt, granulated sugar, or fish sauce as needed. Add 1 1/2 teaspoons of the sesame seeds and half the herb mixture, and toss to combine. Transfer the cucumber mixture with the juices to a serving platter. Drizzle with 1/4 to 1/2 teaspoon chile oil if using. Sprinkle with the remaining 1 1/2 teaspoons sesame seeds and remaining herb mixture.