I was eating at a *sub making* restaurant the other day and they asked if I would like my flatbread toasted... I responded with a "No thanks."

The *Chef* said, "Well technically the flatbread still **HAS** to be toasted, so would you like the meat toasted ?" 

In confusion, I asked, "Why? I would prefer it un-toasted."

The *Chef* said, "We are required to toast all flatbread, as it releases *some* chemical... or something."

Can anyone clear up what he may be referring to?  Does flatbread (non-homemade) **HAVE** to be toasted / cooked / microwaved ?