Unable to boot OSX though UEFI. AsRock, Dual Boot

[p0mmeluff]

Hi guys.

I managed to install 10.11.6 on my PC (UEFI mode) and used MultiBeast for the post install setup, installing the Clover v2.3k r3423 UEFI Boot Mode. But my UEFI menu doesn't show any entries to boot from. No Clover, no Windows, nothing. I have to boot OSX though the Clover boot loader, that is on the USB drive.

I read many threads with similar issues, which usually suggested to download a newer Clover Version etc, but I guess, in my case, this is not the issue. I suspect that I'm not able to boot to Clover from EFI on my hard drive is related to either my AsRock mainboard or / and the fact that I am trying to achieve a dual boot setup with Windows 10, which is installed on the first physical drive as you can see below. And as far as I know, Windows is kinda.. well, a bitch when it comes to dual boot / EFI settings, because it assumes that it is the one and only OS on the PC.

Any suggestions how to fix this issue? How do I get a Clover entry in my UEFI boot options?
I want to avoid uninstalling Windows 10 on my other SSD.

System Specs: Xeon 1231v3 on an AsRock H97M Pro4, GTX 970.

/dev/disk0 (internal, physical):              <---- Windows 10, was installed before
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *250.1 GB   disk0
   1:         Microsoft Reserved                         16.8 MB    disk0s1
   2:       Microsoft Basic Data                         249.6 GB   disk0s2
   3:           Windows Recovery                         471.9 MB   disk0s3
/dev/disk1 (internal, physical):              <---- New OSX install
   #:                       TYPE NAME                    SIZE       IDENTIFIER
   0:      GUID_partition_scheme                        *256.1 GB   disk1
   1:                        EFI EFI                     209.7 MB   disk1s1
   2:                  Apple_HFS macOS                   255.2 GB   disk1s2
   3:                 Apple_Boot Recovery HD             650.0 MB   disk1s3

 

[p0mmeluff]

After a day of reading, trial and error, I managed to fix it.
Thought I'd share my solution with you, in case someone might have the same issue:

- Booted a Live Linux and deleted all boot entries via efibootmgr - that stopped my UEFI from freaking out with display errors on the quick boot selection screen (F11) and got rid of some dead entries of old OS installs
- Reinstalled OSX while the SDD with Windows on it was unplugged, incl. Unibeast
- Manually added a boot entry for Clover via efibootmgr while booting a Live Linux
- Plugged in the Windows SSD, unplugged OSX SSD
- Fixed Windows' EFI partition via bootrec from a Windows Install ISO, so that it shows up in UEFI again
- Plugged in the OSX SSD and adjusted the boot order in my UEFI (Clover first)

Now I am able to boot both OSX and Windows 10 via Clover!