I did it some time ago to run an iMac Pro off a Samsung T3. Basically I think you just use an existing PC or virtual machine to install Windows to the drive, then add in Apple's device drivers once it's booted.
On the Mac Pro 7,1 you'll have to turn off the security boot stuff through recovery mode (command-R while starting up), and use Boot Camp Assistant just to download the drivers to put on a USB key (menubar command). I did both today with no issue, Windows 10 installed very smoothly (on the partitioned Apple SSD).
Edit:
here's a guide.
They use a free trial of VMWare as the PC.