Place the cucumbers on a cutting board, and slice each cucumber in half lengthwise. Then cut into 1 ½-inch thick slices and and use a meat mallet or heavy flat object to pound the cucumbers until they smash and flatten slightly.
Transfer the smashed sliced cucumbers to a strainer set over a bowl. Sprinkle the cucumber with salt and mix until well combined. Rest for 30 minutes to allow the liquid to drain from the cucumbers.
Meanwhile, make the dressing by whisking together the shallot, lemon juice, olive oil, mint, sumac and black pepper in a serving bowl.
Use a paper towel to dab the cucumbers dry. Transfer the dried cucumbers on top of the dressing and toss to coat. Sprinkle the feta cheese and toasted sesame seeds on top and serve.
Notes
Storage: Kept in the fridge in an airtight container, this salad will last for a couple of days. Enjoy it cold, straight from the fridge!