Take the turkey out of its plastic wrapping the day before cooking, pat it dry with paper towels. Leave it resting on paper towels in a large baking dish and covered with paper towels in the fridge overnight.
The next day, take the turkey breast out of the fridge 2 hours before cooking. Remove the string. Brush it with olive oil, then rub about 2 tsp of salt all over the breast.
Carefully arrange the strips of prosciutto around the breast. It can be done by one person, but it’s easier if you have someone on hand to help. Tie the strips of prosciutto around the breast with fresh string (about 5 pieces), and tuck the herbs into the string.
Rest the breast on a rack in the middle of a roasting tray. Pour in the water and the wine.
Preheat the oven to 200ºC (180ºC fan-forced) and roast it for 20 minutes.
Turn the temperature down to 150ºC (130ºC fan-forced). Check that there’s still liquid in the bottom of the tray. If not, add equal parts of water and wine to the tray. Then roast the turkey for another 20 minutes per 500 g. It's hard to be precise as everyone's oven is different. If you have a meat thermometer, the internal temperature will measure 65ºC when it’s cooked through, and the juices will run clear.
Remove from the oven, cover with foil, and rest for 1/2 hour. Remove the string with scissors and carve when ready to serve. Pour some of the pan juices over the top and serve the remainder in a jug. Serve with cranberry apple sauce on the side.