I've already done my due diligence and searched through Microsoft's help forums which didn't have any solutions as usual.
What happened?
My computer froze/locked up (so the only way to fix it was holding down the power button) to force shut it down. When I turned it on again, it installed some update automatically (even though I had updates paused).
Since then, the start menu and the search bar next to the start icon are completely broken. The search bar doesn't respond to typing, and the start menu icon does nothing when clicked.
I've been looking for any instructions on how to roll back updates. All of the instructions given require Windows key + I (which opens the start menu - but that's broken). I also tested Windows key + R, then type in "control" to open the Control Panel but there's no option to roll back updates in there.
UPDATE #1: I already tested the Windows Recovery Environment (https://docs.microsoft.com/en-us/windows-hardware/manufacture/desktop/windows-recovery-environment--windows-re--technical-reference?view=windows-11), which "ran into a problem and won't be able to uninstall the latest feature update". Unsurprising considering Microsoft's recent record of quality problems.
UPDATE #2: I found the option in Windows Recovery Environment to access system restore points - it's currently restoring to the last good configuration. I'll post an update after evaluating the outcome. If this fixes it, I'll post a step-by-step instruction of how to do this and answer my own question.
WHAT SPECIFICALLY I AM ASKING FOR: How do I get the start menu working again? Alternately, how do I roll back the bad update when the UI to do so is missing?
NOTE: I do not want to wipe my computer or reinstall Windows. Any answer involving "wipe and start again" will be downvoted/rejected. I have also read Creators Update Broke Start Menu and found it's not a solution because the person who posted ended up wiping the computer and starting again.