Ok, have you already created bootable USB using
this guide??Read the guide, you will understand better what I say.
Example:
First of all you have to install Mojave in your laptop.
Suppose your secondary hard drive is called disk3, to create a bootable EFI partition as I did:
1: Repartition secondary HDD(Erase all data contained):
Code:
# repartition /dev/disk3 MBR, two partitions
# first partition, "CLOVER EFI" FAT32, 200MiB
# second partition, "Data", HFS+J, remainder
diskutil partitionDisk /dev/disk3 2 MBR FAT32 "CLOVER EFI" 200Mi HFS+J "Data" R
Now you have 3 disks in your system; OS, CLOVER EFI, Data.
2: Install Clover in "CLOVER EFI"
3: Copy content from your CLOVER EFI(USB Drive) to CLOVER EFI(hard drive).
4: Remove USB drive.
4: Go to Bios setup and choose the Clover partition created as boot disk.
5: Enjoy