Question Cast phone screen to Chromecast?

I have a client who has a M7 and a Tab Pro 10.1 and he wants to know how to stream the screen of his tablet to his TV or PC at his office to use for a demonstration and use kind of as a remote whiteboard. He saw someone doing it at a meeting he went to last week, but did not ask how they were doing it. I have searched all around and it looks like he has to be rooted to do it, but it seems unreliable and I don't want to have to fix or set this thing up every time he uses it. I am sure he wont mind rooting his tablet if it means he will be able to stream his screen. I was hoping Chromecast would be able to do it easily, but it looks like that is not a feature yet and it can only be done fairly reliably through Chrome on a computer.

Has anyone done this yet? What do you recommend?

He has a:
HTC One M7
Tab Pro 10.1 (stock)
Intel Nuc running Windows 8.1 Pro 64 connected to the TV
Vizio 70" TV

Thanks in advance!
Android it is...

T-Mobile HTC One ARHD xx.xx
Nexus 7 CM 10.2