Start this recipe by preparing the pork. Hammer the medallion slightly to get an even size, then lay out onto your work top. Place a slice of feta cheese onto each piece of pork and cover with a sage leaf. Wrap up each with a slice of prosciutto. Heat a large pan with a tablespoon of oil and fry the pork medallions for a few minutes on each side, making sure to cook them right through. Remove from the pan and prepare the couscous. In the same pan with all the meat juices, heat another tablespoon of oil and fry the garlic and onion together till soft. Add in the diced zucchini, apple and rosemary and cook for 3 minutes. Add in the couscous and coat in the pan juices before adding in the warm vegetable stock. Cover the pan with a lid and cook the couscous for 3-4 minutes. When ready, stir in the lemon juice and zest. To serve, place a few spoonfuls of the couscous on a long plate and decoratively lay 3 pork medallions overlapping each other in front of the couscous. Sprinkle a few mint leaves over the couscous and serve.