Bring two saucepans of water up to a boil with a pinch of sea salt.
Blanch the kale in boiling water for 3-4 minutes, refresh under cold water and drain well.
In a blender add the kale, brazil nuts and olive oil blend to a smooth paste.
Cook the linguine following the on pack instructions reserving some of the pasta water, drain and add back to the pan with the kale pesto, butter and a splash of the pasta water over a medium heat. Stir to coat well and serve immediately.
Garnish with chopped brazil nuts and grated parmesan if desired.