Rinse the cucumber, peel it and cut it in half lengthways. Remove the seeds and chop the cucumber pulp into fine cubes. Rinse one lemon with hot water and grate off half of the peel. Press the juice from the lemons. Stir the lemon juice with salt, pepper and sugar. Firmly mix this together with the olive oil. Add the smaller cucumber cubes and grated lemon peel.
Rinse the fennel bulbs, clean them (save some of the fennel green) and chop very finely. Cut the salmon into small cubes.
Mix the fennel with the salmon, cranberries and the cucumber lemon dressing and immediately arrange. Rinse the fennel green, chop it roughly and sprinkle it over the salad.