Not using a kitchen thermometer on frozen meats
When cooking meat, you may believe you can tell when it's ready to eat simply by looking at it. That is most emphatically not the case. You have no idea if the meat is safe to eat unless you use a kitchen thermometer. The USDA recommends using this handy gadget when cooking frozen meats to avoid undercooking. Undercooked meat may contain bacteria and be unsafe to consume.
A kitchen thermometer will tell you when the meat has reached the proper internal temperature and will help provide the best overall flavor and texture for optimal enjoyment. To get the most accurate reading, place the thermometer in the thickest part of the meat. Always avoid the bone when cooking any type of meat.