So, I have considered this ingenious idea long ago but had only been reluctant out of pure laziness. But today I make my way over to TJs before lunch and purchased a loaf of "Food for Life" brown rice bread. I then brought a couple slices to my office's cafe for lunch. I toasted the bread and handed it over to our sandwich maker Lucy. It was just as good as the "real" thing. Consider doing the same if you are stuck with limited gf options.
Bring Your Own Bread