Here’s a bento assembled mostly from leftovers and stock foods - from my mother’s Japanese kitchen that is!
In the top compartment: shinmai or new harvest rice, topped with some chirimenjako  - semi-dried little fish - and a couple of slices of a type of long-keeping pickle called narazuke.
In the bottom compartment: herrings (nishin) stewed with umeboshi plum; stir fried green bell pepper; nimame  or stewed beans; tamagoyaki ; squid and vegetable ohitashi ; and a piece of stewed atsuage fried tofu.
The only thing made fresh was the tamagoyaki - everything else was either already stocked in the freezer or refrigerator, or storebought (the chirimenjako and narazuke). The rice was from freezer stock . It took about 20 minutes to assemble, what with making the tamagoyaki and so on, but could have been done more efficiently I think.
I realize this is a pretty classically Japanese bento, but I thought it would be fun to show one like this - just to see what people (or rather, adults) have for bentos here! The stewed herrings were really delicious, sweet and savory with just a touch of acid, but my mother really doesn’t have a recipe per se, so I’ll try to work one out soon.
The box I used is a gorgeous magewappa . I’ll have more about this box pretty soon…