Heat the oven to 200C/fan 180C/gas 6. Tip the garlic, parsley and butter together in a bowl, season generously with black pepper and a pinch of salt, then beat with a wooden spoon or squish through your fingers until everything is combined. The butter can be prepared up to a day ahead and chilled or made two weeks ahead and frozen. Soften before using.
Place the turkey crown on a board with the thick part of the breast facing away from you. Use your hands to make two pockets between the skin and the meat, then smear the flavoured butter beneath the skin and all over the breast and work it down so that the breast is completely covered. 3 Tip the new potatoes into a large roasting tray. Sit the turkey on top, skin side up, then roast for 30 mins. Remove from the oven, sit the turkey on a board and give the potatoes a good shake. Then place the turkey back in the tin, spoon over some of the buttery juices and continue to cook for another
40-50 mins until the turkey is dark golden. Transfer the turkey to a board to rest, loosely covered in foil, then continue to cook the potatoes for 20 mins to brown. Use a slotted spoon to scoop the potatoes into a serving dish, reserving the buttery juices in the pan. Put the potatoes to one side and keep warm.
To make the cranberry gravy, place the roasting pan on a lowish heat and stir in the flour. Let everything sizzle and brown, then add the cranberry sauce and a splash of port. Sizzle everything for a few mins until really sticky, then stir in the stock, bring to the boil and cook until thick or to your liking, seasoning to taste. If the gravy is on the pale side or a bit too sweet, stir in a splash of soy sauce.