Cut the cucumber into long, thin slices using a vegetable peeler and put them in a shallow, non-metallic bowl. Mix the vinegar with the sugar, stir in the dill and pour over the cucumber. Season well with salt and pepper, cover and leave to pickle in the refrigerator for 3–4 hours.
Thread a herring fillet or roll-mop herring on to a wooden or bamboo skewer with some of the cucumber slices. Repeat with the remaining herring and cucumber to give you 15 skewers. Serve at room temperature with the Pink Beetroot & Soured Cream Dipping Sauce (see below), if liked.