Microwave popcorn? Not exactly a "dish" though.
it's not like my grandfather didn't know how to make popcorn, and he never had a microwave.
actually, one cool thing i just remembered was when a friend of mine took one of those small pencils (the kind you get at golf courses), set it lying on top of a styrofoam cup, and turned the microwave on. sparks shot out either lead end of the pencil.
Its pretty cool if you stick a candy bar with the wrapper on in the microwave too
Grape races
Yeah that too.
Make you own drill/death ray/EMP generator too...
http://www.engadget.com/2006/08/23/researchers-create-microwave-drill-death-ray/
DIY smelting @ home: http://www.popsci.com/diy/article/2003-09/smelting-microwave
Chicken into rubber.
When I was back home at Christmas my old dear had these chicken in a bag deals. You bung the bastard in the microwave for 45 minutes and they come out perfect, tender as. Double bagged (hehe) open one when you put it in and it steams away, very tasty indeed, skin and all. Must have been you Americans that invented them I'm sure. I'm sold.
