No, Hamilton Beach slow cooker inserts (the ceramic or stoneware cooking pots) are not safe for use in microwaves. These inserts are designed for slow cooking in a slow cooker and are not suitable for microwave use.
The ceramic or stoneware inserts used in slow cookers are not microwave-safe due to the material and the way they are constructed. Microwaving these inserts can cause them to crack, break, or even shatter due to the rapid heating and uneven distribution of heat in the microwave.
If you need to reheat food from your slow cooker, it's best to transfer the food to a microwave-safe container before microwaving. Additionally, always check the manufacturer's guidelines and instructions for both your slow cooker and microwave to ensure proper usage and safety.