Preheat oven to 350°F (175°C).

Remove papery skin from garlic head, slice top off to expose cloves.

Wrap garlic in foil and bake for 45-60 minutes, or until cloves are soft.

Let garlic cool for 10 minutes.

Squeeze the roasted garlic pulp from the cloves.

Peel potatoes and slice them thinly.

In a large pot, combine sliced potatoes, bay leaf, and 1/4 teaspoon salt.

Cover the potatoes with cold water and bring to a boil.

Reduce heat to simmer and cook until potatoes are tender, approximately 10-15 minutes.

Drain potatoes, reserving the cooking liquid.

Discard the bay leaf.

Mash the potatoes with the roasted garlic pulp, buttermilk, and the remaining salt.

Thin the mashed potatoes with the reserved cooking liquid until desired consistency is reached.