Cut potatoes: Wash, peel, and cut the potatoes in half. For larger potatoes, cut into quarters.
Boil Potatoes: Bring a large pot of salted water to a boil. Add the potatoes. Let potatoes simmer on medium heat for 20 minutes, or until potatoes are tender.
Warm milk and butter: When the potatoes are almost done, add the milk and butter to a small saucepan. On low heat, warm the milk until butter has melted. Turn off the heat.
Drain potatoes: Once the potatoes are done cooking, drain and return back to the pot. Let all the liquid evaporate on medium heat.
Mash potatoes: Mash the potatoes using a hand masher, stand mixer, or potato ricer. Add the warm milk, butter, roasted garlic, chives, salt and pepper.