A rather unusual alternative to basil pesto, this uses more specialist ingredients than I usually go in for but looked so interesting I couldn't resist trying it out. It was delicious. If you can't get hold of green peppercorns, I'm sure black would be fine. Be careful to use unsalted pistachios or this would be far too salty. The recipe I used called for parmesan but since I am a strict vegetarian, I substituted for strong cheddar. However, feel free to use parmesan (or a vegetarian equivalent if you can find it) instead. The recipe I used actually called for double the quantities here and it made a lot of pesto so I've halved it to a more manageable amount. I kept mine in the fridge for a couple of weeks and it was fine.
