• Preheat oven temperature to 350°F.
• Add gluten-free flour, fresh rosemary sprigs, celery stalks, and sliced onion to oven bag. Spray inside of bag with gluten-free non-stick cooking spray.
• Brush thawed turkey with olive oil, finely chopped fresh rosemary, salt, dried sage, garlic powder, and pepper. Place the turkey on top of vegetables and rosemary in bag.
• Close bag with tie; cut six ½-inch slits in top of bag. Place in a roasting pan and cook turkey at 350°F according to the cooking time chart in the notes below.
• For brown, crispy skin, cut open the top of the oven bag 15 minutes before the end of the estimated cooking time (see notes below).
• The turkey is done when the meat thermometer reads at least 165°F in several places not touching the bone. Always check doneness with a meat thermometer.
• Let turkey rest for 15-20 minutes before carving.

Rosemary Turkey Gravy

• While the turkey is resting, add turkey drippings to a medium saucepan. Using a flour sifter or mesh sieve, sift cornstarch over drippings, to prevent clumping.
• Cook over medium heat, whisking constantly, until mixture is smooth and bubbly.
• Whisk in liquid and heat to boiling. Whisk constantly and boil for 1 minute.
• Whisk in salt and pepper. Serve with rosemary turkey.