Total calories (approx): 570 (how calories are calculated) 
Time needed: 5 minutes in the morning
Type: Not Japanese, omnivore (beef), frozen
If you have access to a microwave and a refrigerator at work or school and you’re really pressed for time, you could bring a readymade frozen dinner to work. As long as you don’t have a very long commute the frozen items should stay intact en route, and at lunch time you can enjoy a piping hot lunch. But a frozen bento combo that you make yourself would be healthier and cheaper, and you’d know exactly what was in it too.
I’ve been trying to work out good frozen bento combinations recently, and this partially frozen one has been a big hit. You can assemble it in a few minutes in the morning as long as you have some pre-made individual portion shepherd’s pies  or something similar in the freezer. It’s really a great way to use up pre-planned leftovers without a lot of effort.
Be sure the box you’re using is microwave safe. I use a plastic lunch box rather than a bento box for this.
Put the frozen shepherd’s pies and a handful of edamame in the box.
Take some raw broccoli florets. I don’t even cut them - I just reach into the refrigerator vegetable bin and rip a handful of florets off, and give them a quick rinse. Tuck the florets snugly around the pies in an attractive manner. You could use frozen broccoli here, but that tends to get watery, so I prefer fresh.
Cover the whole thing with a bit of plastic film. This isn’t really to protect the contents during transit, but will be used later on when you microwave the contents.
Here’s the whole lunch. The small container has things that you don’t want to microwave: cherry tomatoes, a couple of cornichons, and a tablespoon of mayonnaise (in the pink paper cup).
Store this in the refrigerator, not the freezer - you don’t want the broccoli to get frozen, and the pies will just defrost slowly. At lunchtime, remove the lid of the main box, tuck the plastic wrap around the contents (it doesn’t have to be airtight), and microwave on HIGH for 5 to 6 minutes more or less, depending on the wattage of the oven you’re using. To see if the pies are warmed through, stick a fork into one and feel the tines to see if they come out cold. If so, zap it for a couple more minutes.
The broccoli gets nicely cooked to a crisp-tender stage. Eat with the mayonnaise. The pies will be piping hot.
If you don’t have access to a microwave at work/school, you will microwave this in the same manner at home and bring the cooked bento. But really, this is a bento that is best when it’s hot, so you could save it for a day when you’re working at home. Or assemble this as readymade meal for your spouse or kids when you are out!