1. In a large sauce pot over medium heat, simmer the potatoes in lightly salted water until cooked and are easily pierced with a sharp knife in the center.
2. Blanch the curly kale in boiling water for one minute. Drain and reserve.
3. Chop half of the spring onions roughly and the other half finely. Add the roughly chopped scallions/ spring onions to the drained kale and pulse in a blender for 10 seconds.
4. Drain the potatoes and add the butter. When the butter has melted, mash the potatoes until smooth and creamy. Add the kale mixture and mix.
5. Finally, add the finely chopped scallions/spring onions and season to taste.