Put the potatoes in a large pan of cold water, bring to the boil, and simmer for 12-15 minutes until tender. Drain and mash with the milk and butter until smooth.
Stir the spring onions through the mash, season with freshly ground black pepper and serve immediately.
Cook’s tip: leftover champ is a great base for bubble’n'squeak. Add whatever other leftover veg you have, such as sqaush, peas or cabbage, and shape into patties. Fry in a little hot oil until crisp and golden, then serve with cooked rashers of bacon.