Use any cookie cutter you like. It's a perfect bento lunch box filler for a family outing.Even on mornings when you've overslept, you can make this really quickly instead of making an omelet.
I came up with this recipe to make something nice with boiled eggs when I didn't have enough time to make an omelet for a bento lunch box.
If you make hard boiled eggs at night, you can save a lot of time in the morning.
Enjoy Japanese food around the world.