Method:
1 Preheat oven 200°C fan-forced.
2 Process pistachios in a food processor until finely chopped.  
3 Heat oil in a frying pan over medium-high heat add lamb and cook for 1-2 minutes on each side.  Remove from pan.  Rub pistachio over the top of the lamb. Transfer lamb to a baking paper-lined oven tray and roast in the oven for 10 minutes for medium rare or until cooked to your liking. Rest for 5 minutes.
4 Heat oil in a saucepan over medium heat add onion and chilli and cook for 2-3 minutes or until softened, add vinegar and cannellini beans and lemon rind, cook for 1-2 minutes or until warmed through.  Using a potato masher, roughly mash the beans, season to taste with sea salt and freshly ground black pepper.
5 Spoon the mashed beans onto a plate and top with sliced lamb and rosemary to serve.