Bring a saucepan of water to a boil and stir in the salt. Add the cloves of garlic and boil them for 2 minutes. Then drain the garlic and return to the saucepan. Add 2 fresh bay leaves, Maldon salt, black pepper, and the whole milk. Bring the milk to just barely a simmer on low heat and cook for 45 minutes. Be very careful not to let the milk boil over. You want it on the lowest simmer possible.

Drain the garlic. At this point you can save the milk for another use, like a soup but we don’t need it for the sauce. Squeeze each clove of garlic from its sleeve and into a saucepan. With a whisk, turn the garlic into a uniform paste. Then stir in the heavy whipping cream and the salt and white pepper. Begin to reduce the liquid on medium heat. When the sauce is reduced to the point that it will coat the back of a spoon, stir in the sherry vinegar and remove from the heat. It ends up reducing by around ⅓.

Preheat your oven to 400° F convection.

Drizzle the olive oil in a roasting pan and lay down a bed of rosemary sprigs. Add the spatchcocked chicken, cut side down, and season both sides with salt, pepper, and olive oil. Then into the preheated oven for about 45 minutes, or until the skin is golden and internal temperature is 165° F at the deepest part of the breast. Remove from the oven and set the chicken aside to rest while you finish the sauce. I let my chicken rest for at least 10-15 minutes.

Carve the chicken and pour the sauce liberally over each serving.