Tear the roll into pieces, pour the milk over, let soften, squeeze out, and push through a sieve.
Mix in the egg yolks and the whole egg, season with salt and pepper, add the parsley, the diced hard-boiled egg and the breadcrumbs - mix into a smooth, thick filling.
Cut a deep pocket into the leg of veal with a sharp knife, fill with the stuffing, and sew the opening closed with kitchen string.
Place in a greased roasting pan, pour 100 ml water underneath.
Preheat the oven to 180°C, roast for about 1 hr 15 min to 1 hr 30 min, basting generously with its own juices every 15-20 minutes.
The meat is done when a meat thermometer reads 70°C at the thickest part, and the surface is a lovely reddish-brown.
Rest for 10 minutes, remove the string, slice, and serve with the strained pan juices.
Based on: Malatinszky Fanny szakácskönyve (a classic Hungarian cookbook), modernised. Calories and protein are estimated.