linux – How to remove Ubuntu entry from EFI and/or reinstall OpenBSD boot loader?

I have a ThinkPad E15 gen 2 AMD laptop. It has the stock Toshiba NVMe SSD and an Intel Optane NVMe SSD. NVMe0 is a spare drive and NVMe1 is the OpenBSD drive.

I had to do something with a disk archive that I couldn’t do with OpenBSD so I installed Mint to NVMe0 once done I wiped the disk and thought I would be golden. That was not so.

Now every time I reboot my laptop I get a grub prompt with no entries. I checked the UEFI BIOS and there is an entry for Ubuntu in there. I’ve instructed the BIOS to lower the priority of this Ubuntu entry, delete it, to no avail.

I want to know how to restore the OpenBSD boot loader and remove the Ubuntu issue for good.