Your system would continue to work as long as you don't turn it off. So no matter what you do, keep it on until you restored your /boot
Recovering it should be straightforward, assuming you didn't put custom files directly to /boot.
Just reinstall the linux kernels using apt. Then manually run grub-install with appropriate parameters. Finally, run update-grub or grub-mkconfig to recreate the grub config.
If the system is turned off, you can use live USB and chroot to it to properly install the kernel packages.
Then to confirm it would restore the system, I deleted everything on root path. as in /
I'm a noob, so forgive me if I'm being very ignorant here, but how on earth could that be a good idea? It sounds like "in order to see if I've installed these airbags correctly I shall now crash head first into this concrete bridge foundation at max speed"?
I'm assuming it's a fresh install, so nothing of value was lost if the restore failed. But also I've heard attempting to delete things in /sys and /devcan brick your computer. So it's not a great idea.
Can't find an article for it at the moment, but I can tell you real quick how I would've done it.
Use aptitude and look for linux-image-amd64 or something under Installed -> kernel. The exact name might be a bit different.
View the package and look under the Version and check out the one that's marked 'i' (for installed). Select that package and mark it to reinstall (shortcut 'L').
Then finally execute it (shortcut 'g' and then 'g' again).