01 - Place potatoes in a large pot and cover with cold water. Add a generous pinch of salt and bring to a boil over medium-high heat.
02 - Reduce heat to medium-low and simmer for 15-20 minutes, or until potatoes are fork-tender.
03 - Drain potatoes thoroughly in a colander, then return them to the hot pot to evaporate excess moisture.
04 - Add butter, warm milk, salt, and pepper. Mash with a potato masher until smooth and creamy. Adjust seasoning to taste.
05 - Serve immediately, topped with a pat of butter if desired.