Preheat the oven according to the instructions on the turkey packaging. Finely grate the zest from the orange and lemon into a small bowl and stir in 100g of the softened butter. Add the thyme and parsley. Season with freshly ground black pepper and mix well until evenly combined. Cut the orange and lemon into quarters.
Remove the giblets from the turkey cavity. Lift the skin from the neck of the bird and use your fingers to ease the skin from the breast meat. Push the flavoured butter evenly under the skin to coat the meat, then smooth the skin back down. Stuff the smaller neck cavity with the sausagemeat stuffing, if using, then pull the skin back over and secure with a cocktail stick underneath the bird. Pop the 3 bay leaves inside the large cavity with the orange and lemon quarters.
Transfer the turkey into a large roasting tin, melt the remaining butter and generously brush over the bird. Season, then loosely cover the turkey with foil, to stop it browning too much. Calculate the cooking time and cook according to the instructions on pack.
About 30-40 minutes before the end of the cooking time, remove the turkey from the oven and take off the foil. Weave the bacon rashers into a criss-cross lattice pattern across the breast. Arrange the pigs in blankets and stuffing balls, if using, around the bird and return to the oven for the remaining cooking time, or until the turkey is thoroughly cooked through, the juices run clear when skewered in the thickest part and there is no pink meat. If the juices are pink, return the bird to the oven for a further 15 minutes then test again.
Transfer the cooked turkey to a warm serving plate and cover with buttered foil. Leave to rest in a warm place for at least 30 minutes (or for up to an hour). Serve the turkey with the pigs in blankets and stuffing balls, garnished with bay leaves.