To roast the garlic: Pre heat oven to 400 degrees. Place a baking sheet in the oven as it pre-heats. Remove some of the outer layers of garlic skin if they're plentiful. Cut the top off the head of the garlic and place in foil. Drizzle with olive oil and sprinkle with salt and pepper. Seal foil and place on baking sheet. Roast for 30-40 minutes. Allow to cool before using. When cool, squeeze the roasted cloves (discard the skin) and set aside to use in the dip.
To make the dip: Preheat oven to 350 degrees. Combine all ingredients. When well mixed, spread into baking dish. If you want more cheese, sprinkle Parmesan cheese on top. Bake 35 minutes. Serve with pita chips, grilled Italian bread or raw vegetables.