Total calories (approx): 645 (how calories are calculated) 
Type: Pasta salad!
I love pasta salad—it’s a perfect hot weather meal. But I am just a bit wary about bringing a regular pasta salad as a bento lunch, since it may be sitting around at room temperature for some hours. This pasta salad solves that problem by not mixing mayonnaise in the pasta, but adding chunks of frozen tuna salad with mayonnaise . The frozen chunks keep the box cool, and defrost nicely by lunch time. The pasta is pre-flavored with a little olive oil and lemon juice as well as being mixed with a healthy portion of one of my favorite standbys, sweet pepper and onion confit  and the tuna salad with mayo acts as a sort of additional sauce. The combination of flavors and ingredients is inspired by a classic salade niçoise.
I used macaroni made with spelt for this, since whole grain pastas are a bit healthier than pasta made of white flour. But I have a pack of colorful (and rather expensive) pasta shaped like trumpets or lilies. I just cooked a handful of these with the spelt macaroni, and used them to decorate the top. You could use any kind of fun or decorative pasta this way (Japanese bentos often do this actually).
To do the night before:
Cook the pasta. For every cup of pasta you make, add 1/2 Tbs. of olive oil, a sprinkle of salt, black pepper and about a teaspoon of lemon juice (I just squeeze some in). If you’re using decorative pasta, hold them aside. Mix with the sweet pepper confit. At this point you can add more cooked vegetables - I added some sauteed zucchini.
You will want to boil the egg (1 per portion) the night before too.
In the morning:
Add any raw vegetables you want to add to the pasta—I added a bit of chopped celery and parsley for a bit of crunch. Put into your bento box, and tuck in a few small chunks of frozen tuna salad. Arrange the boiled egg wedges, decorative pasta, cherry tomatoes and olives on top.
As you can see, by making most of the components in advance, assembly takes less than 10 minutes.