You will purchase a packet of Regency Pop-Up Timers, of course! This little device is designed to give you the perfectly cooked turkey, every time. All you have to do is insert the little spear into the breast of the turkey (being the densest part of the bird), and when the meat reaches the correct temperature for cooking perfection, the red insert will pop out of the holder and alert you to the fact you are now a successful turkey-cooker. The timers come in a pack of two, so in reality, you will only need to buy them biennially! Just don't forget where you put them between Christmases.
Of course, as you can use these with all your poultry, you need never have another chewy chook, or tough ol' turkey, again.