What a crock of UEFI Shit eh ? New fangled stuff is right n good when it works. and the info is clear to find.
The shiny new BIOS will allow you to add a boot option. The BIOS will already know the magic PCI partition.
You must specify a path. The Boot Path.
Just enter: \EFI\BOOT\BOOTX64.EFI
And all should be good again.
If you don’t, If you try and boot off the actual HDD, you will get the black screen and blinking cursor of information, which is the culmination of 30 years of user interface design and error trap reporting.
Well done all involved. well fucking done.