Quote Originally Posted by georgie_leech View Post
In practice, pockets of molten cheese continue to sit beside Frozen bits in our hot pockets
There's another reason for that behaviour--microwaves basically work by heating the water in the food, but they're not very good at heating ice. Since the heating is also uneven, as you say, and the clumps of ice are of differing sizes, you will tend to get bits that melt first and then heat very quickly while the other bits are still frozen and not absorbing microwaves very well. This is why you're supposed to stir frozen things partway through cooking, or else leave them to stand for a couple of minutes to allow the hot parts to melt the still-frozen bits.