Piercing or taking off the plastic film lid from frozen family meals like lasagna or eggplant parmesan before cooking can lead to undesirable results for a few reasons:
Moisture Retention: The plastic film lid helps retain moisture within the container during the cooking process. By keeping the lid on, the moisture is trapped, which prevents the food from drying out and maintains its texture and flavor.
Even Cooking: Leaving the plastic film on ensures that the heat is distributed evenly throughout the entire dish. This helps prevent some parts from overcooking while others remain undercooked.
Splatter Prevention: During cooking, frozen meals can release liquids and oils. The plastic film acts as a barrier, preventing these liquids from splattering all over the inside of the oven or microwave. This makes for easier cleaning afterward.
Food Safety: In some cases, the plastic film lid is specifically designed to withstand the cooking temperatures recommended for the meal. Removing it may expose the food to potential contamination, especially if the plastic is not safe for high temperatures.
It is generally better to follow the cooking instructions provided on the packaging for frozen family meals. Cooking a bit lower and slower with the plastic film lid on ensures that the dish is cooked thoroughly, remains moist, and retains its flavors. If the instructions recommend using the plastic film lid during cooking, it's best to follow them for the best results and overall food safety. If you have any concerns about using the plastic film during cooking, you can check the manufacturer's guidelines or consider transferring the meal to an oven-safe dish with a lid that can withstand the recommended cooking temperatures.