Preheat the oven to 200˚C.
place the nduja, lemon zest, butter and shredded leaves in a bowl. Stir to combine. Keep aside covered until needed.
Bring to boil the potatoes in a large saucepan filled with water and seasoned with salt.
Simmer for 20 minutes until fully cooked. Remove from the heat and drain the water.
Place the potatoes on a baking tray and crush or smash each potatoes on the baking tray. Drizzle with some oil and if desired add a spoon or two of nduja butter.
Place in the preheated oven and roast for 20 minutes until crispy. Keep warm until needed.
Preheat a griddle pan over high heat. Rub some oil on the striploins and season well.
Place on the pan and grill for 2-3 minutes then turn the steaks and continue to grill for a further 2 minutes. Reduce the heat to medium heat and add extra butter. baste the steaks with the butter and continue to cook for a further 2-4 minutes until cooked to your liking . remove an set the steaks on a board or plate to settle the juices.
Serve the steaks with the crispy potatoes and a dollop of the nduja butter.