Wash the meat and pat dry, cut off fat and tendons. Season meat with salt and pepper. Heat lard in a flat roasting pan. Fry the meat in it over a high heat for 6-8 minutes. Put the meat in the roaster into the preheated oven (electric cooker: 80 °C/ convection oven and gas: unsuitable) and roast for approx. 4 1⁄2 hours
Chop apple slices, mix with 100 ml lukewarm water and leave to stand for approx. 30 minutes. Wash the thyme, shake dry. Pluck the leaves from the stalks and chop them, except for a little to garnish. Mix mustard, apple jelly, thyme, butter and white bread crumbs. Put apples on a sieve, drain and squeeze out a little. Knead the apples and 1 tbsp. coarsely ground pepper into the butter mixture, season with a little salt and after approx. 2 hours frying time spread on the roast beef
Remove the roast beef and let it rest for a short time. Then cut into thin slices, arrange on a plate and garnish with thyme. Serve with remoulade and a salad