Let me first say that, while I would like to say I'm an experienced computer user, this was an absolute stroke of idiocy on my part.
I have a Dell G15 that has a 1 TB NVME. I wanted initially to resize the EFI partition to from 100 MiB 2 GiB (Windows default), as I was trying to install arch, and it failed to boot (I assumed that the reason for this, due to the fact that grub couldn't write to the partition, was that it was full). The existing EFI partition was bordering a Windows install, and I didn't want to disturb that in hopes of recovering it in the future (at the time, neither arch nor windows could boot). I read that the EFI partition doesn't actually have to be the first partition on disk, however, so I just created a new EFI partition alongside my arch root partition (which I resized) and life was good. And then I deleted the original EFI partition.
What I thought would happen is that the system would give me an error saying that it couldn't find any bootable media and redirect me to a firmware menu.
Instead, what happens is that the firmware happily does it's thing until it reaches the dell splash screen. Then nothing happens. I have pressed all the usual keys (F2/F12, tried delete as well), and the menus do not pop up. I suppose the menus were actually EFI executables that were in that first partition which get ran after the firmware startup, but since I deleted it, it can no longer access them.
There is a way I can theoretically recover from this, which is to open my laptop up, take the NVME out (assuming it's accessible), put it in my desktop, and use the arch install medium I have to try to rebuild it. The data / file system is still there, so hypothetically I can just recreate the partition.
My question is that, bar opening up my laptop and desktop (which is my last functional computer), is there any way to get some sort of response out of my laptop that can let it boot to my recovery medium?
Responses to comments: I have not tried to open up of the laptop yet and ideally want to avoid doing this, but resetting the firmware is a logical next step, and this avoids me having to open up my desktop, so thanks.
Pressing (or holding) the usual F2/F12 keys as well as other common ones (esc/del) doesn't work at all.
I figured that the EFI partition doesn't have to be 2 GiB, but I did see that if a user wants to install multiple kernels, 2 GiB is recommended, and I wanted to give myself the room just in case.
I don't think legacy/BIOS compatible mode was enabled on my machine when I had UEFI access, and all my partitions were UEFI capable, but I cannot say for certain now.