I don't know what that phraseology translates to in term of real world objects (two Welsh Rarebits on top of each other?) but my experience in the US of you guys drenching everything in several tons of plastic melted glowing cheese-substance suggests I'd want to steer clear.
Thats cheezwhiz or velveeta. It aint right. The closest place to acceptability is that apparently some Philedelphians consider cheezewhiz the proper cheese for a Philly Cheesesteak sandwich.
I have not yet been able to eat an authentic Philly Cheesesteak from Philedelphia to confirm this or not.
Outside of this, any other use of cheesewhiz is or velveeta is considered a crime against humanity per the Wisconsin Accords of 1915.