Linux from scratch booting up
 

Following the LFS book and using Gentoo, All the steps were right until the very last step. When I unmount and reboot the system I do not see the LFS I built.

The LFS book uses BIOS method to boot up and my device is a UEFI, Do I have to do something different for UEFI systems? If not what could be the issue ?

How are you booting Gentoo? You will need to add your new LFS to the existing bootloader menu.

Follow the link to the blfs page in the lfs grub setup section uefi note