Does anyone actually manage to do that? I'd be awfully impressed. It sounds like a beautiful system, but seems to be marred by human fallibility. I try sometimes, but inevitably wind up simply buying whatever looks tasty at the market and then having to spontaneously generate meal ideas from what's sitting around. And something gets forgotten, and then suddenly there's a disturbingly moldy cucumber languishing in the bottom of the crisper.
On the plus side, bento is a singularly spectacular mechanism for dealing with forgotten bits and pieces. Go some random still-food-but-just-barely lunchmeat? Chop and add to fried rice*. Sad greens? Enough sesame oil covers a multitude of sins. Borderline slimy mushrooms? Delicious in everything.
Consider this yellow squash. After being out of town for a week, I looked through the fridge and realized that while we'd tried to use up perishables before vacating, there was one lonely and slightly shriveled squash in the drawer. Poor thing.
sad squash gets new life
I summarily chopped it up and sautéed it, along with some fresh broccoli, in chili sesame oil and plenty of Sriracha**, and paired it with rice with some frozen leftover ham and some green onions. It was downright delicious, if a bit spicier than I'd expected. But then, one of the beauties of trying different combinations all the time and making up recipes as I go is that we get to experience a big range of flavors in manageable lunch-sized portions. Experimenting with dinners often results in tubs of leftovers that then must be eaten whether you liked the dish or not. But a lunch? Even if it's sub-par, so what? It's just a lunch. I overcooked the broccoli a little in this one, so it was kinda limp and greyish. Oops. Lesson learned, with pretty minimal harm done.
Anyway, the point of this is that bento is a great way to use up random otherwise-perplexing small amounts of just about anything.
* Heating properly to make it bento-safe, of course.
** Have I mentioned lately that Sriracha is amazing? Sriracha is amazing.