Perhaps it is effectively radar that cooks stuff, and which can thus theoretically beamform and read directional reflections to detect where the food is. Becau

Perhaps it is effectively radar that cooks stuff, and which can thus theoretically beamform and read directional reflections to detect where the food is. Because it is mostly-enclosed, it can theoretically additionally detect how much energy isn't going back into the closed loop, and thus went into the food. Disclaimer: I am not a radiologist.