Preheat oven to 400F.
Keeping head of garlic whole, peel away loose papery exterior. Cut just the top off the whole head of garlic and discard. Place garlic on aluminum foil and drizzle with olive oil, then sprinkle with salt and pepper. Take up ends of foil to form a package around the garlic and roast in preheated oven for 20-30 minutes. Allow to cool slightly.
Once garlic is cool enough to handle, unwrap from foil and place on cutting board (not wood, preferably). Using the non cutting edge of a knife, start at the un cut end of the garlic and press and squeeze the softened garlic from the head. Trim any tough tops and using the same knife, smear each clove against the board. The cloves will easily become a paste - roasting the garlic sweetens and softens it beautifully.