What was the silver disk inside the cardboard pot pie box that caused crust browning in the microwave oven?
These things are called microwave susceptorsThey are made up of a material (typically a metal like aluminum flakes) that strongly absorbs microwave radiationThis materials is embedded in a heat-resistant polymer and coated as a thin film on a part of the packaging Do a search for microwave susceptor on your favorite search engine and you'll get lots of hits from manufacturers of these things.
