It turns out that he runs a weekly session for actors interested in... well, in being better. And once a month at the Royal Court, there's a late night demonstration of some of the stuff they do.
It's semi-improvised - he has a plan and they do the improv :)
So on Friday, there was something on how in plays by Pinter, the first word of each person's speech is the one he thinks about most. Cue some improvised examples, followed by a scene where the first word of each speech is in alphabetical order, A-Z.
Next, something about how in Mamet's plays, it's the last word that's critical and how often his lines will just end in the middle
Cue more improvised examples, followed by a scene where the last letter of each speech is in alphabetical order...
Throw in some Campbell rambling and a few more exercises (like a song about how, if you come to the Royal Court, you're gonna feel pain and suffering) and a very enjoyable hour was had.