Preheat oven to 175degC/350 Fahrenheit
Heat 2 tablespoons of the melted butter in a large fry pan. Add onion and cook for 2 minutes, until soft. Add apple and sage and cook for a further 2-3 minutes until apple is soft. Transfer to a large bowl.
Add cranberries/cherries/apricots, breadcrumbs, milk, cashew nuts, eggs, remaining melted butter, salt and pepper to the apple and onion mixture, and mix until well combined.
Rinse turkey out with water. Clean out the cavity, discarding the neck and offal, and pat turkey dry with paper towels. Place on a large chopping board. Fold wing tips under it’s body and leave legs tied together. Place 1/2 cup stuffing into the cavity, using your hands to compact it. Repeat until the cavity is full (you will most likely have some stuffing leftover). Roll any remaining stuffing into balls to be roasted later.
Transfer turkey to a large roasting dish and pour water around it (this will help to cook the turkey evenly and keep it moist). Brush or rub turkey with olive oil, squeeze over lemon juice (this helps it brown) and sprinkle with salt. Roast for 1 hour, then reduce oven temperature to 160degC/320 Fahrenheit.
Arrange onion wedges and any stuffing balls around the turkey and drizzle with olive oil and vinegar. Return to oven to cook for a further 40-55 minutes or until the little thermometer pops out indicating the turkey is just cooked through. Remove, cover with tinfoil and tea towels and let it rest for at least 15-20 minutes before carving and serving.
To serve, transfer turkey, onions and stuffing balls to a very large platter and decorate with sage/rosemary (if using). Serve with warmed cranberry sauce on the side. Toast your fellow Christmas guests and dig in! Merry Christmas!