Rinse 1 cucumber, trim off the ends but do not peel. You can cut grooves lengthways with a small knife or special tool (shown in the photo), if you prefer this look, but it is not essential.
2: Slice the cucumber thinly (a mandolin is the ideal tool for this). Sprinkle the slices with fine salt, mix well and leave for to rest for 30 minutes.
3: Prepare 4 tomatoes and slice fairly thinly. Sprinkle with fine salt, mix well and leave to rest for 30 minutes. This helps to bring out the full flavour of the tomatoes and cucumber.