Boil one-third of the potatoes until tender, drain well, and mash smooth. Finely grate the remaining raw potatoes and squeeze very dry in a towel, reserving the liquid.
Let the reserved liquid stand, pour off the water, and add the settled starch to the raw potato. Mix with mashed potato, egg, potato starch, and salt.
Combine pork with the grated half of the onion, marjoram, and pepper; divide into 12 portions.
Shape and Cook:
Flatten a portion of potato dough in damp hands, enclose a pork portion, and shape into a smooth oval. Repeat to make 12 dumplings.
Lower dumplings into gently simmering salted water and cook 25 to 30 minutes without a hard boil.
Finish:
Cook bacon until browned, add diced onion, and cook until soft. Drain dumplings and serve with the bacon mixture, sour cream, and dill.
Notes
Keep hands damp while shaping to prevent sticking.
A gentle simmer helps prevent the dumplings from breaking.