Preheat the oven to 350°F.

With a sharp knife, slice about ½ inch off the top of the head of garlic. Stack two 6-inch squares of aluminum foil. Place the garlic in the center and lift the sides to form a cup. Drizzle with the olive oil and sprinkle with the oregano, salt, and pepper. Enclose by twisting the edges of the foil together to seal.

Place on a baking sheet and roast 20 to 25 minutes, until entirely softened. Open the foil and set aside to cool. When cool enough to handle, squeeze to remove the garlic cloves, discarding the skins.