Separate the garlic cloves, but do not peel them. Pile them on a piece of aluminum foil, drizzle with olive oil, and fold the foil over them to form a sealed packet. Bake the garlic in a 375° oven for about 45 minutes, or until the cloves are soft.

Peel the potatoes and cut them into 2-inch chunks. If you prefer your mashed potatoes with their skins, just scrub them, trim them, and cut them up. Put the potatoes in a pot with enough well-salted cold water to cover them by ½ inch, bring the water to a slow boil, and cook them until they are completely tender. Drain the potatoes, reserving the cooking water. Return the drained potatoes to the pot.

Squeeze the soft garlic out of the cloves and discard the skins. Press the garlic through a strainer and add the pulp to the potatoes, along with the butter, buttermilk, and salt and pepper to your taste. Mash thoroughly with a potato masher while the potatoes are still steaming hot. Add a little of the cooking water if the potatoes seem too dry. (The rest of the water can be saved and used for making bread if you’re so inclined.) Taste, and adjust the seasoning.