Update: These steps should no longer be necessary if you are using the latest release of ElementaryOS which seems to have fixed the UEFI issues.
There is a problem with the latest ElementaryOS (0.3.1) installation image when used on a UEFI only system; in our case this was a Dell XPS 13 (9350) laptop. The installation completes but you are presented with a grub> prompt when you restart the laptop.
You can use tab to complete the grub commands
grub> configfile(hd <tab>
For our installation the file we are looking for paths as follows:
grub> configfile (hd0,gpt1)/boot/grub/grub.cfg
Which should then boot the laptop normally. Once the laptop has booted into the ElementaryOS installation we can fix the problem permanently.
$ sudo cp /boot/efi/EFI/grub/grubx64.efi /boot/efi/EFI/grub/grubx64.efi.broken $ sudo cp /boot/grub/x86_64-efi/grub.efi /boot/efi/EFI/grubx64.efi $ sudo reboot
You should now have a fully working ElementaryOS installed on your UEFI system.