Step 1

Using a mandoline (or a knife), thinly slice cucumbers 1/4 inch thick. Transfer the cucumber slices to a fine-mesh strainer set over a large bowl; sprinkle with sugar and salt. Toss to combine. Let stand at room temperature for 30 minutes.

Step 2

Discard any liquid in the bowl and wipe the bowl dry. Transfer the cucumbers to the bowl and toss with onion, vinegar, dill and pepper. Let stand at room temperature for 15 minutes. Serve immediately or refrigerate for up to 3 days.