The phrase "lunchbox staple" refers to a food item or ingredient that is commonly included in a packed lunch. It is something that is usually found or expected to be present in lunchboxes regularly. Full definition
It's a glorious time for enjoying this autumnal fruit, and in this post I'll show you how to transform kabocha squash into a delicious lunchbox staple: kabocha salad. (provincialpaleo.com)
Was my kid the only one out there who wouldn't touch that quick and easy lunchbox staple, the sandwich? (thelunchtray.com)
Baby carrots and sliced apples with dipping sauces are other healthy lunchbox staples. (childdevelopmentinfo.com)