1. Peel and slice the cucumbers. Thin slices are better.
2. Peel and slice onion into very thin slices and add to cucumber slices.
3. Mix mayonnaise, vinegar salt & pepper and pour over sliced cukes and onion.
4. This dish tastes better when the cucumbers have had time to marinate in the dressing. You can make it the day before and keep it stored in a plastic container in the fridge.
5. Serve chilled.