As a general rule, it is not recommended to put a frozen dinner directly in a toaster oven. Toaster ovens are typically designed for toasting, baking, and reheating smaller items, but they may not have the necessary features or space to safely and properly cook a frozen dinner.
Frozen dinners often contain multiple components with different cooking requirements, such as meats, vegetables, and sauces. These meals are usually intended to be cooked in conventional ovens or microwaves, which provide more even and consistent heating to ensure the meal cooks thoroughly and reaches the appropriate internal temperature to kill any harmful bacteria.
If you try to cook a frozen dinner in a toaster oven, you may end up with uneven cooking, potentially undercooking some parts and overcooking others. Additionally, the limited space and heating capabilities of a toaster oven could lead to safety issues or even damage the appliance.
For best results and safety, it's always recommended to follow the cooking instructions on the packaging of the frozen dinner. If the instructions specify using a conventional oven or microwave, it's better to stick to those methods. If you don't have access to a conventional oven, a microwave is a safer alternative for heating frozen dinners.