I've talked about Horopito quite a bit.
To make a pepper - take a couple of hand fulls of leaves (make sure no bird strike!)
Dry until crispy in a fruit dryer (or you can microwave - or dry in an oven)
Dry very slowly to keep the flavour.
Then place all the leaves in a seal able plastic bag and crush by hand to get a lovely Horopito pepper.
Experiment with usage - I have found their is quite a variation (in heat) with Horopito plants.
Also remember that Horopito has a slow creeping heat.
Horopito is deliciously spicy - It goes brilliantly with lamb.