Quickly rub the cold lard into the flour, add the egg yolk, sour cream and salt, and knead into a dough; wrap in plastic and chill for 30 minutes.
Cut the meat into cubes, sauté the onion in lard until translucent, remove from the heat, stir in the paprika, immediately add the broth, and braise covered over low heat, like a stew, for about 45-50 minutes, until very tender.
Cut the tender meat into small pieces or chop it coarsely.
Cook the macaroni pieces in salted water for about 8 minutes, then drain.
Add the macaroni, the braised mushrooms, the parsley, the sour cream and the butter to the meat, and fold together.
Roll out two-thirds of the dough and line a greased round baking dish with it.
Fill it with the filling, roll out the rest of the dough as a lid, and pinch the edges together.
Bake at 180°C for about 1 hour, until the top is golden brown; serve sliced, lukewarm.
Based on: Malatinszky Fanny szakácskönyve (a classic Hungarian cookbook), modernised. Calories and protein are estimated.