Prepare the potatoes by peeling and cutting them into even chunks. Place in a large saucepan, cover with cold water, and add salt. Boil for 15-20 minutes until tender.

Slice the spring onions, separating the white and pale green parts from the dark green tops.

In a small saucepan, heat the milk and butter over medium-low heat until the butter melts. Add the sliced spring onions and simmer gently for 2 minutes.

Drain the potatoes and return them to the saucepan over low heat to evaporate excess moisture. Mash until smooth and creamy.

Gradually pour the warm milk and onion mixture into the mashed potatoes while stirring continuously.

Season with salt and black pepper, then garnish with the reserved green spring onion tops before serving.