Prepare the cucumber: Slice your cucumber lengthwise then scoop out the seeds with a small spoon. Next, gently smack cucumbers on their skin side with a rolling pin or the back of a chef's knife until they begin to break apart. Tear into bite-size pieces. Transfer to a colander; toss with a few big pinches salt and let sit 10 minutes to drain excess liquid.
For the vinaigrette, whisk together lemon juice, Dijon, olive oil, salt and pepper until emulsified.
Drain the cucumbers and combine with remaining ingredients. Toss with vinaigrette to taste. Enjoy!