Can I "re-caramelize" meat after a failed braising attempt?

I gave it a shot! I took the oxtails out and seared them in a cast iron pan underneath the broiler in my oven. Once they were pretty much blackened on all sides, I dropped in a bit of the stew and simmered it down very briefly using residual heat from the cast iron. It was a surprise how quickly it infused with the caramel flavor from the meat. I added the reduction and meat back to the original stew and it has a decent, robust flavor like I'd hoped. Not ideal, but a good way to compensate for expenses in "cutting corners".

The one downside is that my "fast braise" in the cast iron seemed to have diminished the seasoning slightly. I rinsed and wiped the pan dry then coated with some oil and put it back under the broiler briefly.

In theory, it should work out okay. I've never tried it, personally.

If you are going to pull them back out and attempt to heat them directly again, I would suggest patting them dry first, so that other components of your stew that may be stuck to the meat do not char and add a burnt taste.