Heat the oven to 150°C (130°C in a fan oven), 300°F, gas 2.
Grind the pepper corns and mustard seeds in a mortar and rub into the meat.
Heat the clarified butter in pan and fry the meat on all sides on a very high heat. Then wrap in aluminium foil and cook for approx. 1 hour (The core temperate should be 60°C). If desired cook for a little less to keep the meat pink.
Bring the red wine, lemon juice, sugar, cinnamon stick and the allspice seeds to the boil. Place the apples in the hot liquid and steep on a low heat for approx. 15 minutes.
Just before the meat is done, remove the foil and season well with salt. Leave to rest for 5 minutes before slicing.
Slice the meat and arrange it on the rocket along with the apples. Garnish with feta chesse.