Cook potato in skin until soft (like for potato salad). When ready peal the skin and mash potato on flat surface. Be careful it is very hot.
Add butter (crush it a bit to speed melting), flour, semolina, nutmeg and salt. Make it into a dough, and when cools it a bit add two eggs. You will think now that you make a big mistake because it will turn very wet, but you have to be firm and continue to make dough. It is OK to add more flour.
The right amount of flour will be clear to you after you make this several times, this is amount I usually put. It also depends on quality of potato; some are softer than others. When the dough is firm, but soft enough, make the dumplings.
Cut a piece of dough and roll around cleaned and washed plum. The dough shouldn’t be more than 1 cm thick. If you make it without plum stone, break the plum into half, remove the stone and put a sugar cube instead. After that, do as previously mention.
At this point you can freeze the whole amount of dumplings, but do it on flat surface making sure they don’t touch. After they freeze, you can put them in a bag.
If you want to cook them right away, use large pot, fill with water up to 2/3 and add some oil. When water boils, put the dumplings into the water and cook until they start to float on the surface. You may use a toothpick to check if they are soft.
In the meantime melt butter in a frying pan and fry some breadcrumbs. When removing dumplings from the pot put them into hot butter with breadcrumbs and fry them just a bit to reduce surplus of water.
You may serve them as a desert, but also as a lunch, of course amount of dumplings will differ in both cases.
When you open the dumplings, you may put some sugar over it and also some grounded cinnamon. Some people add sour cream over dumplings, but I don’t like it that way.