Prepare the vegetables and place them along with the bay leaves and thyme in your baking dish.
Sprinkle on the salt and pepper, and give them a good stir.
Roast the turkey for 40 minutes.
Reduce the heat to 150° C (300° F) and keep roasting the turkey for another 2 hours, or until the meat is fork tender.
Leave the turkey to rest for 15 minutes while preparing the gravy. Place the baking dish on low heat. Add stock and scrape the bits off the bottom of the pan.
Let the gravy bubble for 15 minutes, pass it through a fine sieve, and transfer it into a small saucepan. Add slurry, and any juices from the resting turkey.