Using a mandoline or a very sharp knife, slice the cucumber and fennel. Chop the shallot, I always slice them in fine half moons. Arrange the cucumber in shingles overlapping each one slightly and forming concentric circles. (For my Dutch friends: leg de komkommer schijfjes dakpansgewijs over elkaar ). Then arrange the fennel and shallot over the cucumber.
Whisk the sugar, salt and vinegar in a bowl until the sugar has dissolved. Taste it and add more sugar or salt according to your own taste. Sprinkle the dressing over the vegetables and let them marinade for 10 minutes.
Roast the sesame seeds in a dry pan. Don’t loose them out of sight, they will burn within seconds! When the sesame seeds have cooled down, sprinkle them over the salad. Finally chop the dille and add it to the salad as well. Finish with a good amount of freshly ground black pepper.