Quite simply, if you’re comfortable with the Virutal Machine manager UI, create a VM like normal, and when it comes to giving it a storage volume, just give it a tiny dummy volume that will be discarded ASAP.
Then, find the directory where the virtual machine configurations XML files are found. A typical location would be /etc/libvirt/qemu/ but could differ.
In that, find the section where the stub of a storage volume exists, it’ll look something like this:
<disk type='file' device='disk'>
<driver name='qemu' type='qcow2'/>
<source file='/home/user/VM/HDD-Stub.qcow2'/>
<target dev='hda' bus='ide'/>
<address type='drive' controller='0' bus='0' target='0' unit='0'/>
</disk>
and swap the type from a file to a block, and change the driver to a raw type, and finally the source from a file to a device, which is the particular disk drive to passthrough.
<disk type='block' device='disk'>
<driver name='qemu' type='raw'/>
<source dev='/dev/sdb'/>
<target dev='vdb' bus='virtio'/>
</disk>
The target/bus depends on what type of interface or drivers one will have available. Most notably during a Windows installation a virtio bus won’t be recognized right away, requiring extra drivers to be given at installation time from somewhere reputable such as Red Hat or the Fedora Project.