Could I set up a course at the ATO I work, and go land at Crossland Moor, Octon and Glenswinton and give a thorough theory course on hot/high operations?! Would that count?
No, it would not. I say again, there are no airfields in the UK designated as requiring a mountain rating (nor are there ever likely to be). We're talking about something more like this:
For a mountain rating (ski), at least one of the landing surfaces has to be on a glacier - you don't find too many of those in the UK.