I saw this lovely Braided Spinach Feta Bread over at Artisan Bread in Five (did you buy the book yet?) and wanted to make something so pretty. Mine didn't turn out quite as lovely as his, which is funny because he says his isn't as pretty as Zoe's. Nevertheless, they're all pretty. :)
I think I've made it three times now, each time stuffed with different things. Once for dinner with friends to be kinda fancy. Later, when we were out for the day, it made an easy cold picnic lunch. And a third time to use up leftovers. It's easier than it looks, and basically any meat/veggie/cheese/sauce/herb combination would work as a filler.
I used the Challah dough for the first two, and maybe the basic dough for the third. I forget. Quick, tasty, and pretty every time!