I installed Juno a couple weeks ago on a new laptop. I have elementaryOS on one hard drive and Windows 10 on a second hard drive -- no partitioning, just physically separate drives.

When I initially installed eOS, it didn't install Grub, I don't think. At least, the Grub menu didn't appear when I booted; it would boot automatically into eOS and, if I needed Windows, I would manually select it from the BIOS boot menu. This is how I like it, because I barely use Windows.

Today, I booted up and the Grub menu came up after the logo splash screen. I don't know if it got automatically installed in an OS update maybe? But as I understand it, it should be unnecessary, because my OSs are on separate physical drives; is that not the case?

I've searched around for how to remove Grub but all of the instructions I've found are for removing Linux entirely, which of course I don't want to do. How do I go back to booting directly to Linux? And, how do I prevent Grub from getting automatically added like this, if indeed it is part of a routine OS update?