Place potatoes in a large pot and cover with cold water. Bring to a boil over medium-high heat, then reduce heat to low and simmer for 10 minutes, or until potatoes are tender.
Drain potatoes and return them to the pot. Add butter, milk, salt, and pepper, and mash with a potato masher or a fork until desired consistency is reached.
Serve warm.
Interesting Facts
Mashed potatoes are a popular side dish in many cultures.
Adding butter to mashed potatoes gives them a creamy, rich flavor.
Mashed potatoes are a great way to use up leftover potatoes.