Peel the majority of the cucumbers lengthwise into thin slices using a peeler. Cut the rest into different shapes (for example, cubes or sticks).
For the vinaigrette, mix all ingredients together well and season to taste.
Divide cucumbers among four plates and arrange nicely, marinate with the vinaigrette.
Spread the feta and avocado on the cucumbers and serve the carpaccio sprinkled with cilantro.