Step 1

Trim the ends of each cucumber, then halve lengthwise. Place each half cut side down, and, using a rolling pin or meat pounder, pound the halves until they split and crack. Scrape out and discard the seeds. Cut the smashed cucumbers into rough ¾-inch pieces.

Step 2

In a colander set in a large bowl, toss the cucumbers with ½ teaspoon sugar and 1 teaspoon salt. Top with a small plate, then weigh it down with 2 or 3 cans. Let stand for 15 minutes.

Step 3

Meanwhile, in a small bowl, stir the vinegar, oil, fish sauce, the remaining 1 teaspoon sugar and ¼ teaspoon salt. Stir in the shallot and jalapeño. Let stand until the cucumbers are ready.

Step 4

Discard any liquid that has accumulated under the cucumbers, then rinse and dry the bowl. Lay out a kitchen towel, spread the cucumbers on it and pat them dry. Transfer the cucumbers to the bowl along with the shallot mixture. Toss, then taste and season with salt. Transfer to a shallow serving dish. Sprinkle with the peanuts and cilantro.