Remove the thin papery outer skin that covers each whole head of garlic. (Either peel it off starting from the root or take a knife and cut around the covering midway up the head, then peel off the outer skin.) Place the heads in a small baking dish. Drizzle a little oil or butter over them and sprinkle on salt and pepper. Bake 1 to 2 hours, depending on size, until tender. Serve one head per person.
To cook in a microwave, drizzle the peeled garlic heads with oil and cook 1 to 12 minutes at full power.