Well that was dirtier than expected! EGR was caked with build up. Surprised it hasn't been bucking and acting up prior to now, and even now it was only on a rare occasion that just started a few days ago.
Before:
After (I did end up cleaning inside a bit more after the picture):
Didn't think it was actually going to be as easy as all the Insight guru's predicted but it turned out to be quite a simple task.