Do not thaw.
Appliances vary, adjust cook times accordingly. For food safety and quality, cook to an internal temp. of 165°F as indicated by a food thermometer.
Microwave(1100 Watt): Cut slit in center of film covering tray. Put tray on a microwave-safe plate and microwave on high for 5 ½ minutes or until internal temperature reaches 165°F. Remove from microwave. Let stand for 1 minute. Carefully remove film, slice and serve.
Oven: Preheat oven to 350°F. Carefully remove film from tray before baking. Cover frozen tray of meatloaf with foil and place on a baking sheet in the center of the oven. Heat for 60-65 minutes or until internal temperature reaches 165°F. Let stand for 5 minutes. Carefully remove foil, slice and serve.