I'm a very big fan of making something once and using it for as many meals as possible. I made cornbread muffins to go with a dinner, and doubled the recipe to have enough for leftovers and lunches.
These lunches all have two cornbread muffins (recipe is here - but it's an old post so you'll have to forgive the terrible pictures), with a container of honey butter on the side. Honey butter is simple - just mix soft butter with honey until it's a consistency and flavor you like. That's all. On the side they have berries, cheese, cereal, and some little cookies.