COOK: Dice potatoes into 1-inch pieces. (TIP: For a smoother texture, peel potatoes first.) Peel two cloves garlic. Place potatoes and garlic in a large pot with enough salted water to cover by 2 inches. Bring to a boil, then reduce to a low simmer. Cook until potatoes are tender, 15-20 minutes, then drain. Return potatoes and garlic to pot and cover to keep warm.

MASH: Add 3 TBSP butter to pot with drained potatoes and garlic. Mash until smooth. Stir in sour cream and half the milk. Season with plenty of salt and pepper. Keep covered off heat until ready to serve.

FINISH: Just before serving, stir another 3 TBSP butter into pot with potatoes and garlic. (TIP: If needed, heat pot with mashed potatoes over medium heat first, until potatoes are warmed through.) Add splashes of remaining milk as needed until creamy. Transfer to a serving dish and cover with foil.