Final answer:
A food worker must engage in regular handwashing and use a thermometer to ensure the chicken stir-fry reaches an internal temperature of at least 74 degrees Celsius (165 degrees Fahrenheit) to kill any bacteria.
Step-by-step explanation:
Before cooking a large batch of chicken stir-fry, a food worker must take certain precautions to ensure food safety. Most importantly, the food worker should engage in regular handwashing, which is one of the most effective defenses against the spread of foodborne diseases. After cleaning their hands thoroughly, they should also use a thermometer to ensure that the chicken stir-fry reaches an internal temperature high enough to kill any bacteria it contains, which is at least 74 degrees Celsius (165 degrees Fahrenheit). These steps help prevent foodborne illnesses and ensure that the chicken stir-fry is safe to consume once fully cooked.