Hi Tox and ruserious,
I find HF very interesting (I first got involved in 2000 and have spent the last 10 months running back to back HF courses all over the place). EASA Part 145 requirement and all aircraft maintenance staff operating under Part 145 had to have received HF training by September 28th.
If you are interested in MRM, follow
this Part 145 carries a syllabus for HF training and
CAP 716 has further information on tailored training.