Where should you insert a thermometer when taking the temperature of a steak?

Inserting a thermometer in the thickest part of the steak is the best practice because this area will provide the most accurate reading of the overall temperature of the meat. The thickest part is typically the last area to reach the correct internal temperature during cooking, and therefore, checking there ensures that the steak has reached a safe and desirable level of doneness throughout.

Placing the thermometer near the bone can lead to inaccurate readings, as bones can conduct heat differently than the meat, resulting in a falsely lower temperature. Checking at the edge of the steak may not provide a representative measurement of the steak's temperature, since the edges cook more quickly and can be hotter than the center. Inserting the thermometer in the marinade would not yield a useful reading for the internal temperature of the steak, as it would measure the temperature of the liquid and not the meat itself, which is the critical factor for food safety and proper cooking.