Begin by peeling and cutting the potatoes into quarters. Place them in a large pot and cover with cold water. Add a pinch of salt to the water.

Bring the pot to a boil over high heat, then reduce to a simmer and cook for about 15 minutes, or until the potatoes are fork-tender.

While the potatoes are cooking, gently warm the milk in a small saucepan or in the microwave until it's just heated through.

Once the potatoes are cooked, drain them well and return them to the pot. Add the butter to the pot with the potatoes and start mashing them to your preferred consistency.

Gradually add the warm milk to the mashed potatoes, continuing to mash until they are smooth and creamy.

Season the mashed potatoes with salt and pepper to taste, and give them a final stir to combine everything evenly.

Serve the mashed potatoes hot, garnished with a pat of butter or fresh herbs if desired.