1. Heat the oven to 180C or 160C (fan-forced).
2. To make the stuffing,fry the bacon in a little of the butter until lightly browned,then add the mince and fry until it is browned. Add the onions and continue to fry until they are translucent and softened. Remove meat mixture from the heat then add the remaining butter to the hot pan,allowing it to melt. Mix the bread cubes into the meat mixture with the butter,and add the parsley,salt and a little stock or water to create a soft stuffing.
3. Rinse the turkey under running water (remove the neck if still attached) and drain well. Stuff the stuffing into both the neck and rear cavities of the bird. Truss the turkey and season all over with salt.
4. Cut the carrot,celery and remaining onion into large chunks and place in the base of a roasting pan with half a cup of water. Place the turkey on top. Cover the entire pan with foil and roast in the oven for two-and-a-half hours. Uncover the pan and roast for a further hour,basting with the pan juices every 15 minutes until the skin is browned. Remove the turkey from the oven and cover loosely with foil. Rest for 30 minutes in a draught-free place. Reserve the pan juices.
5. For the blue cheese dressing,whisk the mayonnaise,yoghurt and lemon juice together until smooth,then stir through the spring onions,cheese and Worcestershire sauce. Season to taste with salt and pepper.
6. To make the Buffalo glaze,stir the butter,sauces,vinegar,mustard and sugar together in a small saucepan over medium heat until warm,then brush some of the glaze generously all over the turkey.
7. Serve the turkey with its pan juices,the remaining glaze,wedges of lettuce and avocado dressed with blue cheese dressing.