If you've removed a commit with git reset --hard, it's still possible to recover the commit using git reflog to look up the commit hash.
Once we find the right commit hash, we can reset our branch back to that commit hash with git reset --hard [HASH]
NOTE! git will actually garbage collect abandoned commits (every 30 days or so - so not very often) - so you can't recover from a reset --hard forever; which is why it's recommended to avoid --hard if you ever want to references those changes.
git reflog
Find the commit id which you want to recover then do:
git reset --hard [AHSH-id]