About thirty years ago, industrial engineers began developing microwave heating techniques that avoid some limitations of conventional heating.
Results often are remarkable.
With microwaves, no heat is applied per se. The molecules in the material then act like miniature magnets attempting to align themselves with the electrical field. The product surfaces may be in danger of over heating by the time heat penetrates the material. Microwaves, however, produce a volume heating effect. It also evens temperature gradients and offers other important benefits.