Place the oil, onion and leeks in a pan with a lid and heat gently for 5 mins until the ingredients soften.
Add the potatoes, stock, Rosemary and seasoning to the pan, replace the lid and bring to the boil.
Turn the heat down low and simmer for 20mins until potatoes are soft.
Add the garlic and using a hand blender, blend all the ingredients together until you reach a smooth consistency.
Serve immediately.
Stir through a little cashew milk and top with extra rosemary sprigs and black pepper.