Heat oven to 400 degrees. Place garlic heads in a baking dish, and drizzle with olive oil. Sprinkle with salt and pepper.
Place baking dish in center of oven, and roast heads until soft to the touch, about 1 hour.
Cut off the tops of the heads, squeeze the soft cloves out of their papery shells, and use immediately.
To store roasted garlic, squeeze cloves into a jar; cover with olive oil, and add lemon juice. Flavor with herbs, if desired. Seal, and store for up to 10 days in the refrigerator.