With Windows Server 2016 Technical Preview 2 Microsoft added the Nano Server, and in this guide you learn to create an bootable ISO file that deploys it. If you want you can also copy the content of the ISO file to a USB stick, make it active, and then you can deploy the Nano Server from the USB stick too.
In this guide I assume you have completed my main Deploy Nano Server using MDT 2013 Update 1 guide so you have a deployment share with a Nano Server reference image and task sequence.
Create the ISO file
To create a bootable ISO file you simply create a MDT Offline Media in the Advanced Configuration node.
1. Using the Deployment Workbench, expand the Advanced Configuration node
2. Right-click the Media node, and select New Media. Specify a folder for the media (I used E:\Nano\ISO)
3. Configure the Media properties (disable x86, and configure the rules to prompt for Task Sequence, ComputerName and to restart when completed (FinishAction=RESTART)
4. Update the Media. Done! You now have a bootable ISO in the E:\Nano\ISO folder.
Note: If you want to deploy from a USB stick instead. Simply format a USB stick (NTFS), make it active, and then copy the content of the Content folder to it.