Most Japanese homes have these small tamagoyaki fry pans for rolled up eggs on the go.  If you know anything about tamagoyaki - you will understand why you need this.  If you don't you might like to read up on it.

Check out our Just Bento cookbook for recipes/tips - because they use it there for sure.  In fact you can see a tamagoyaki on the cover in the bento on Just Bento 2.