Chop the ham finely and mix with the sour cream into a creamy filling.
Roll the four-times-folded buttery dough to the thickness of a knife-back and cut into equal-length strips.
Spread each strip with the ham filling, roll up and shape into crescents.
Brush the tops with egg and bake.
Can also be made as scones: tear off a smaller and a larger round, put the filling between them, brush the top with egg, sprinkle with salt and grated Parmesan (with a little paprika if liked), and bake the same way.
Based on: Malatinszky Fanny szakácskönyve (a classic Hungarian cookbook), modernised. Calories and protein are estimated.