Thanks everyone for you thoughts and comments, in particular Geezha for posting the link.

I have watched a video on here before of someone cooking a naan in a similar way but not taken much notice for some reason, i don't know why.  I really was curious after watching this video and got round to trying it today - lets just say the tandoor order is on hold at present.

Followed video exactly and produced a fantastic naan first time and then another twice to be sure 

What a great recipe and technique, thanks to everyone, esp the cook/chef who took time to make the video