Cut the pork fillet into pieces approx. 2 cm in size, pepper and fry briefly in a hot pan. Deglaze with the meat stock and cook on a low heat for about 10 minutes. Remove meat and keep warm.
Mix the meat stock with the cider and crème fraîche and reduce to about 1/3. Add the calvados and the chopped chives, season the sauce with salt, pepper and nutmeg.
Let the meat steep in the sauce again and serve with pasta, spaetzle, rice or potato gratin on preheated plates.