I've tried that a couple times on my own HP Proliant Server ML110 Gen9. The installation proceeds perfectly, no error whatsoever but no way I can get it to boot

I've tried that a couple times on my own HP Proliant Server ML110 Gen9. The installation proceeds perfectly, no error whatsoever but no way I can get it to boot from the HD. I'm finding UEFI quite hard to debug when compared to MBR + GRUB... I find it odd that the pendrive boots fine, the installation happens well but the HD will not boot. I wish there were more tips for debugging UEFIon their guide.