Place potatoes in large saucepan with enough cold water to cover. Bring to boiling; gently boil, covered, about 15 minutes or until chunks are fork-tender. Drain.
Meanwhile, heat together milk and butter in medium-size saucepan over medium-low until butter is melted and mixture is hot.
Return drained potatoes to large saucepan. Mash with potato masher. Gradually mix in milk mixture and salt and pepper with potato masher until potatoes are smooth and creamy. Potatoes can be kept warm in saucepan, covered.