Peel, wash and roughly grate the potatoes. Wash, clean and coarsely grate the zucchini and add to the potatoes. Stir in egg and flour, season to taste with salt and pepper and mix
Heat the oil in portions in a frying pan. Form the mixture into small Rösti (approx. 5 cm Ø) in the pan and fry for approx. 5 minutes on each side. Remove the finished Rösti, drain on kitchen paper and allow to cool. Process the rest of the potato mixture in the same way
Dill wash, shake dry, flags, except for something to garnish, pluck from the stems and cut finely. Stir mustard and cream cheese with milk until smooth, season with salt, pepper and sugar
Arrange Rösti and salmon slices on plates. Place 1 blob of mustard cream on each plate, sprinkle with pepper if necessary and garnish with dill.