Prepare the potatoes by peeling and chopping them into evenly-sized chunks, about 1-inch pieces.

Boil the potatoes in a large pot of salted water over medium-high heat for 15-20 minutes until fork-tender.

Drain the cooked potatoes well and return them to the pot. Allow them to steam off for a minute or two.

Mash the potatoes using a potato masher or ricer until smooth and creamy, leaving a few small lumps if desired.

Combine the warm milk with melted butter in a small saucepan over low heat, stirring until just combined.

Stir the milk and butter mixture into the mashed potatoes until well incorporated and creamy. Adjust seasoning with salt and pepper.

Fold in finely chopped scallions, mixing until just combined.