I found a workaround, but it was hardly ideal....
I built a room around the grilled food, then used Move Room to drag the room outside into the yard. From there I was able to use the sledgehammer to delete the quarantine room and everything in it, which luckily, included the grilled food!
This left me with a hole in the kitchen, but I was able to drag over the empty space to re-fill in the foundation and floor.
Hilariously, the grilled food is now back in my family inventory, but I will just leave it there until a real solution presents itself.