Peel the potatoes and cook as usual. Then press hot. Immediately mix in the semolina and let the mixture cool down.
As soon as the potato mixture is cold, add flour, egg and salt (the amount of flour depends on the type of potatoes). The mass should be nice and firm. Then halve and shape into two rolls (diameter as desired) - with me they are about 5-6 cm thick.
Then cook these rolls in boiling water for about 15-20 minutes. Finally, remove from the water, cut into slices and serve with a good meal.