Making a delicious meal usually requires precise cooking times, as the line between overcooked and undercooked foods can often be quite thin. But that's not the story when it comes to the mushroom. In fact, it's virtually impossible to overcook a mushroom. To get a better understanding of this, you have to look at the cellular structure of the food. The cell walls in mushrooms are made from a polymer called chitin. Chitin, unlike the protein found in vegetables and meats, is heat-stable, which means it isn't easily altered or destroyed by too much heat. Translation: no matter how long you cook your mushrooms, they'll almost always turn out with a tender and palatable consistency.