1. Scrub potatoes and boil in salted water.
2. Cover spring onion with cold milk and bring to the boil. Simmer for 3 to 4 minutes, turn off heat and let it infuse.
3. When potatoes are cooked, peel and mash while hot. Mix with milk and spring onion.
4. Beat in some butter. Season, add chopped parsley and serve with butter.

Cook’s tip

 Adding hot milk to hot potatoes is the secret to a light and ­fluffy mash. Always use a ­floury potato, such as agria, instead of a waxy variety.