Cut the pork neck into fist-sized pieces. Rub the meat with salt, pepper and marjoram, brush with mustard and drizzle with oil. Put the meat in a deep bowl, pour beer over it and leave to stand for 12 hours, covered.
Let the meat drain off a little while collecting the marinade. Place on a roasting rack to catch the stock too.
Fry in the preheated oven at 175 ° C for approx. 45 minutes on both sides. Deglaze the meat stock with half of the marinade and make a sauce.