1. Lightly sear the beef on a very hot skillet. 2. Set the oven on dry heat at 60°C and core probe temperature at 55°C. 3. Season your seared beef with salt, pepper and the English mustard before placing in a GN and bake until your hear the core probe signal. 4. In large pot slowly sautée the diced carrots and celeriac, adding the diced onions at a later stage. Once your soffritto gains a golden hue, add the apple, brown mustard and lemon. Keep going for another 5 minutes, stirring. Deglaze with wine until it has reduced and the alcohol evaporated. Add the beef stock and the bouquet garni, lower the heat and cook for another 30-40 minutes. Remove the bouquet garni and finish with double cream. 5. Blend the sauce, add butter and pass through a fine sieve while it’s still warm. 6. Season with salt, pepper, sugar and vinegar. 7. Allow the beef joint to rest at room temperature and slice thinly. 8. Plate and pour warm sauce over the meat. Best served with dumplings.