Well, it's certainly doable. Though for meat in particular, people prefer to use stoves, grills, and ovens, because while a microwave can heat up meat to the point where it cooks, you really need a grill or a hot pan, for example, to induce the Maillard reaction on the surface of a steak (give it a good sear), while leaving the inside medium-rare. Try doing that in the microwave...