Add the scallions to milk in a pot on the stove top
Bring to a slow boil and immediately reduce to simmer for about 3-4 minutes
Remove from the heat and let them steep together
Peel the potatoes and cut into fourths
Boil them in salted water until fork tender
Drain the potatoes and let them sit in the colander for a few minutes to remove excess water
Put potatoes back in the pot
Season with salt and pepper and add 5 tablespoons of cubed butter
Mash with a potato masher
Pour in the milk/scallion mixture and stir in with a spatula until well combined
Check for seasoning
Add to a bowl and make a well on top of the potatoes
Drizzle with remaining 3 tablespoons of melted butter
