On another OSX machine (or another Hackintosh), download macOS Mojave from the App Store.
Insert your USB drive and open up Terminal.
Open up Disk Utility to format your USB drive:
Find your USB drive in the left sidebar under External (if there are multiple sub-drives under your USB drive, select the top-most one).
Press the "Erase" button on the top toolbar.
Give the name Installer and make sure to select GUID Partition Map as the Scheme.
Press Erase, wait until it completes, and quit Disk Utility.
Open up Terminal and create the installer
Run the following command
sudo "/Applications/Install macOS Mojave.app/Contents/Resources/createinstallmedia" --volume /Volumes/Installer and type in your password when prompted.
Wait for the process to complete. This can take around 30 minutes to an hour.
Download the latest build of Clover (you'll want the one that ends with .pkg) and install it to the installer USB drive.
Launch the installer pkg you downloaded.
When prompted, choose Change Install Location... and select your USB drive (it should be named Install macOS Mojave).
Next, click the Customize button.
You'll want to check the following options (you can also install any additional theme, but don't check anything else):
Clover for UEFI booting only
Install Clover in the ESP
UEFI Drivers -> ApfsDriverLoader-64 (for APFS support)
UEFI Drivers -> SMCHelper-64 (for FakeSMC support)
UEFI Drivers -> AptioMemoryFix-64 (for FileVault support)
UEFI Drivers -> HFSPlus (for HFS+ support)
UEFI Drivers -> UsbKbDxe-64 (needed for FileVault support)
FileVault 2 UEFI Drivers -> AppleUISupport-64 (for FileVault support)
Once the installation completes, you should see a new drive named EFI get mounted.
Download the HaC Mini release package and merge the
EFI directory into the one on the EFI drive. Replace any existing file (which should just be config.plist).
Safely remove the USB drive.
Insert your newly created USB installer into any USB slot and power on the NUC.
Press F10 at the prompt to get into the boot menu.
Select your USB drive and press enter.
You should see the Clover menu. Select the USB drive.
The OSX installer should load.
Partition your SSD using Disk Utility. You should wipe the entire drive and format it as APFS with GUID Partition Map. This will also create the EFI and Recovery partitions.
Installation will reboot a few times. Each time it reboots, you must press F10 at boot and boot from the USB drive again.
Once in Clover, you should select the drive named Boot macOS Install from ... if it appears.
After installation completes, you should still boot from the USB drive and in Clover, select Boot macOS from ....
Now we will move Clover from the installation USB to your boot drive so you can boot without having the USB inserted.
Open Clover Configurator and choose Mount EFI on the left sidebar.
You should see at least two entries under Efi Partitions. One corrosponding to your SSD where you installed macOS to and another one corrosponding to your installer USB.
Click Mount Partition for both entries and enter your password if prompted.
Click Open Partition on your USB installer's EFI entry and a Finder window should open. Copy the directory named EFI (it should be the only item).
Back in Clover Configurator, click Open Partition this time on your SSD's EFI entry. Another Finder window should open. Paste the directory your just copied. Choose to Replace the existing directory.
In the same Finder window you just pasted into, traverse to EFI and then CLOVER and you should see a file named config.plist. Open this file with Clover Configurator and you should get a new window.
In the new Clover Configurator window, choose the SMBIOS tab on the left sidebar.
Now click the Generate New button next to Serial Number and then Generate New next to SmUUID. This is important because it ensures you have a unique serial and are not using the same static serial as everyone else who didn't follow this guide correctly. Without a unique serial number, some Apple services won't work correctly.
Save your config.plist changes.
You can now eject the USB installer and you no longer need it to boot into the system!