Cut the bacon into fine cubes and drain in a pan without fat. Wash the potatoes and cook them covered in plenty of boiling water for about 20 minutes. Wash cucumber and cut into fine slices with a slicer.
Peel and finely chop the onion. Mix cucumber and onion and season with salt and pepper. Drain the potatoes, rinse and peel them and press them through a potato press. Add egg, starch and bacon to the potatoes and mix.
Season to taste with salt. Form 12 dumplings from the potato dough. Boil up plenty of salted water. Add the dumplings and let them simmer for 15-20 minutes at low heat until they rise to the surface. Remove the dumplings.
Meanwhile, wash the sage, shake dry and pluck the leaves from the stalks. Heat butter in a pan. Sauté the sage for approx. 4 minutes while turning. Add the dumplings after about 2 minutes and fry all around.
Arrange on plates. Add salad.