In a mixing bowl, combine all the ingredients for spice rub. Lightly coat the turkey breast with the oil, then coat with the spice rub evenly all over. Refrigerate for at least 4 hours, then bring to room temperature before roasting.
Preheat oven to 450°F.
On a baking sheet, place carrots, onion, celery, thyme and rosemary. Place the turkey breasts on top of the vegetables.
Roast for 15 minutes, then rotate the pan and return to the oven and lower the temperature to 325°F. Roast for approximately 1 to 1½ hour for an internal temperature of 165˚F. Remove turkey from the oven and let rest.
For the gravy, transfer chopped vegetables and turkey drippings to a medium saucepan with chicken stock or broth, bring to a boil, then simmer for about 10 minutes. Taste to see if it needs more salt or pepper.
In a small bowl, whisk cornstarch with water, then whisk mixture into turkey gravy. Simmer 2 minutes, then strain through a fine-mesh strainer. Serve the turkey with gravy and cranberry sauce.
Recipe by Let's Cook Some Food at https://www.letscooksomefood.com/roasted-spice-rubbed-turkey-breasts/