The smoothest of mashed potatoes are made with the help of a potato ricer and creme fraiche.
Put potatoes and garlic into a large stockpot; cover with cold water. Add 1 tablespoon salt. Bring to a boil; cook until tender, about 10 minutes. Drain. Press through a potato ricer or a food mill into a large bowl, and cover.
Meanwhile, stir milk, cream, butter, and 1 tablespoon salt in a small saucepan. Heat over medium heat until steaming but not boiling. Stir in creme fraiche. Stir into potatoes until just combined; season with pepper. Using a large whisk, whip potatoes until fluffy, 3 to 5 minutes; season with salt.