I had a working dual boot system with Windows 10 and Ubuntu 19.10, both on separate SSDs and decided to remove Windows altogether. I use gparted from a live usb to wipe the Windows 10 SSD altogether but in doing so, I seem to have removed the EFI and GRUB partitions for Ubuntu also. Now my BIOS does not show ANY boot options. Is there a way to recover the EFI boot files for Ubuntu?
My Ubuntu install was running in an lvm partition.
I tried using boot-repair recommended fix but ended up with an error. Here is the pastebin URL with 2,400 lines of text from the boot-info file: http://paste.ubuntu.com/p/nPVcY3NCHm/
This is why I don't recommend folks put both OS on different drives; if both OS were on the same drive, when you removed Windows 10, Ubuntu and its boot files would still be there.
When you install Ubuntu, it asks which partition OR drive to use to store the boot information; I normally use the first drive, not any partition; just /dev/sda (or equivalent).
Then /home and \Users end up on the second SSD, so all the data's together and you only need to back up that second drive frequently.
Can /boot/efi and the GRUB files be recovered? Try the free, Open Source app TestDisk which has oodles of documentation and can be installed for Windows, Linux, and MacOS X to recover files from lvm and many, many, more filesystems.
I'd suggest downloading one of the LiveCDs from https://www.cgsecurity.org/wiki/TestDisk_Livecd and writing it to a USB flash drive; booting from there, and start your recovery.