Using precooked turkey breasts cuts down on the amount of time you need to spend in the kitchen. Most precooked turkey breasts will include a roasting bag that you are directed to keep the meat sealed in while you heat it. When removing the outer packaging, do not to dispose of the bag. Although the turkey is precooked, use a meat thermometer to take the internal temperature of the breast.
Thaw the precooked turkey breast. Leave the turkey breast in the refrigerator for approximately 24 hours to thaw. If you are short on time, submerge the turkey breast in cold water for several hours to thaw.
Preheat the oven to 350 degrees Fahrenheit. When reheating precooked poultry items, never set the oven below 325 degrees Fahrenheit.
Remove and discard the outer-packaging materials. Place the turkey breast in the roasting bag. Seal the breast in the roasting bag without puncturing the bag. Transfer the turkey breast and bag onto a wire rack in a shallow roasting pan.
Pour cold water in the bottom of the roasting pan. Put the roasting pan into the oven.
Bake the turkey breast for two to three hours. The size of the breast determines the exact roasting time. Insert a meat thermometer into the thickest portion of the breast toward the end of the cooking time. A minimum safe temperature, according to the U.S. Department of Agriculture, is 165 degrees Fahrenheit.
Allow the breast to rest for approximately 15 to 20 minutes. Cut the bag from the turkey and discard it.