Start by removing the turkey from the fridge 30-45 minutes before you will cook it.
Preheat your oven to 300 degrees.
Remove the turkey from the packaging. The legs will be tied, leave that on.
Place the turkey on a sheet or roasting pan with the breast side up.
If you have any carrots, celery, or onions, rough cut them up and insert them into the cavity of the turkey. You can put some underneath the turkey as well.
Insert the probe of your thermometer into the deepest part of the breast. Set your thermometer to go off at 140 degrees.
Wrap entire top of the turkey in heavy duty aluminum foil, making sure not to mess up your probe. You don't need to cover the bottom of the turkey.
Cook until the alarm on your thermometer goes off. This could take between 3-4 hours or less depending on your elevation and the size of your turkey.
When you hit 140 degrees, remove the turkey from the oven.
Allow the turkey to rest for 15-20 minutes before carving .
Put leftovers in the fridge as soon you are done eating and they have cooled down.