Remove the rack from the turkey roaster and preheat roaster to 400 degrees.
Place the rack on a large tray (to catch any liquid) and place the turkey on the rack.
Stuff the turkey cavity with sliced apples, onion, and celery.
Separate the skin at the top of the bird from the meat and slide the pats of butter in between the skin and the meat.
Make the browning sauce mixture by mixing together the melted butter and the browning sauce.
Using a pastry brush, generously brush the turkey with the browning sauce mixture. (This step can get messy, so be careful!)
Generously season the turkey with salt, pepper, and the seasoning of your choice.
Insert the meat thermometer into the thickest part of the breast meat, avoiding the bone.
Pick up the rack, and gently place the rack and the turkey in the turkey roaster.
Pour 1 can of chicken stock into the roaster and close the lid.
Cook at 400 degrees for 1 hour.
After 1 hour, turn the temperature down to 350 degrees and cook until the turkey's internal temperature reaches 170 degrees. (Cooking times will vary depending on turkey size.)
Once the turkey is cooked, remove it from the roaster using the rack. Tent the turkey with foil and let it rest for 20 minutes before carving.