Heat the oil in a large saucepan over medium heat, add the onion and garlic and cook for 5 minutes or until softened. Add the potato and stock, bring to the boil and cook for 20 minutes or until the potato is tender. Use a hand-held blender to blend the soup until smooth. Add the kale, chorizo, salt and pepper and cook for 5 minutes or until the kale is wilted and the chorizo is warmed through. Spoon into bowls and drizzle with extra-virgin olive oil to serve. Serves 4.