My instructor, who happened to be the chief flying instructor and staff examiner, pointed to a field and made sure I was looking at the right one, then reduced the throttle to idle and said "oh dear it looks like you have an engine failure".
Tee hee.
The usual advice is that the instructor is looking out of the
right window, so there's usually a better field that way than there is out of the left window, where the student would naturally look first.
However if instructors
only look out of the right window they can get it wrong ... I once got given a PFL when just out of the left window, unnoticed by the instructor, was a bloody great runway!! OK, so disused and somewhat derelict, but not an unreasonable choice for a real forced landing. (I didn't get away with it; when I told him that's where I was going he said "er, right then, that's not a runway, it's a swamp, pick somewhere else" so I had to look out of the right window after all.)