I install the 15.10 version with the Something Else option, and create my EFI partition, as well as my root, home, and swap partitions. I then selected the proper partition (ex. sda1) to install the bootloader and away it goes, however when it's completed there is no entry in my UEFI boot selection menu. I installed Mint the same way (17.3), and with the exception of installing the video driver later, it works flawlessly. Any ideas on what could be causing this?
I have found out a solution on my own. Instead of doing it the other way like 14.04 and putting the bootloader in sda1 (efi partition), just select the full drive (sda). Now it shows up in the UEFI menu and boots fine.