Slice through the garlic head horizontally about a third of the way down from the top, exposing the cloves inside.Place the head of garlic on a sheet of foil and drizzle all over with a generous amount of olive oil.Gather the foil around the garlic and loosely close it at the top.Roast in a 400 degree oven for 45 to 50 minutes. The cloves will be browned and very fork tender.Once cooled, use a fork and/ or your hands to remove each clove from the garlic and place them in a bowl. Smash the garlic cloves with the back of a fork until creamy and smooth.Whisk in the balsamic, olive oil and salt.