For the potstickers, peel the potatoes, cut into quarters and boil in salted water for about a quarter of an hour until soft.
Strain and pass through the potato press.
Stir flour, semolina, salt and egg into the potatoes.
Mix curd, sugar and sour cream with the yolk.
Roll out the dough thinly on a lightly floured work surface and cut into rectangles about 10 x 5 cm.
Spoon the curd mixture onto half of each rectangle, fold the dough together and press the edges well.
Cook the patties in hot salted water (takes about 8 minutes).
Heat butter in a pan and fry breadcrumbs until golden brown.
Strain the potstickers and drain well.
Serve the potstickers sprinkled with toasted breadcrumbs.