Peel the cucumber (or leave the skin on, if you prefer), halve it lengthways and scoop out the seeds. Slice into thick half-moons. Put in a dish with the vinegar, oil, mint and a pinch each of sugar, salt and pepper. Toss together thoroughly, then set aside in a cool place (but not the fridge) for 15-30 minutes. Toss again before serving.
*Recipe from The Guardian