Mark Bittman, writing for the NY Times:
The key, as in so much good eating, is having a well-stocked pantry. I’m talking here not only about olive oil and vinegar and soy sauce, the kinds of things that every cook has. And I’m talking not only about tuna and sardines and maybe bread and tomatoes, the staples of many brown-baggers.
I’m also talking about building blocks, like tomato sauce, a pot of beans (or grains, equally valuable), a pan of roasted vegetables, perhaps even a roast chicken. These are the kinds of elements that you can put together while you’re doing something else — whether cooking a meal or watching a football game or catching up on e-mail — and that will last all week, adding substance, flavor and real appeal to whatever else you have lying around. Get that kind of thing going, and you’ll be overwhelmed not by the challenges of putting together a decent lunch before you leave the house but by the possibilities.
Easier said than done, but my problem at least is mostly just inertia.