After installing funtoo with UEFI+GPT on a dell 7480 according to the wiki, I was greeted with a "no bootable device found" message. It seems that my motherboad expects the file grubx64.efi to be located at /boot/EFI/BOOT/BOOTX64.EFI (my efi partition is /boot).

Copyng the file to the desired location fixes the problem. This fact is mentioned in https://wiki.gentoo.org/wiki/GRUB2 and should be mentioned in Funtoo's installation guide, IMHO.