Preheat oven to 180°C/160°C fan-forced.
Melt butter in a medium frying pan; cook onion and bacon, stirring, over low heat until onion is soft. Cool. Combine onion mixture and remaining ingredients in large bowl; season.
Discard neck from turkey. Pat turkey dry inside and out with paper towel. Fill neck cavity loosely with stuffing; secure skin over opening with small skewers. Fill large cavity loosely with stuffing; tie legs together with kitchen string
Place turkey on an oiled wire rack in a large shallow baking dish; pour 1 cup (250ml) water into dish. Brush turkey all over with half the butter; cover turkey tightly with two layers of greased foil. Roast 2 hours. Uncover turkey; brush with remaining butter. Roast, uncovered, for 1 hour or until cooked through. Remove turkey from dish, cover loosely with foil; stand for 20 minutes.
Pour juice from dish into a large jug; skim 1 tablespoon of fat from juice, return fat to dish. Skim and discard fat from remaining juice; reserve juice. Add flour to dish; cook, stirring, until mixture bubbles and is well-browned. Gradually stir in stock, wine and reserved juice; cook, stirring, over medium-high heat until gravy boils and thickens. Strain gravy into a jug; serve with turkey.
Hold the turkey below the breast with a carving fork. Using a sharp knife, slice straight down one side of the breastbone with an even stroke. The slices will fall away as they are cut. Continue carving the breast until enough meat has been carved for first servings.
To check if the turkey is cooked, pierce the thickest part of the thigh; if the juices run clear, the turkey is cooked. Alternatively, insert a meat thermometer into the thickest part of the thigh, without touching the bone; the turkey is cooked when the thermometer reaches 82°C.Test Kitchen tip