Wash and peel the sweet potatoes
Cut them into evenly sized chunks
Place them in a pot and cover with cold water
Add a pinch of salt if desired
Bring to a boil over medium-high heat
Reduce to a simmer and cook until fork-tender, about 15 to 20 minutes
Drain well
Return to the pot or a bowl
Mash with butter, milk, salt, and pepper to taste
Serve immediately