Makes a generous 3/4 cup
Preheat oven to 325 degrees.
Cut the top quarter from each head of garlic and place cut side up onto one side of a piece of aluminum foil cut to measure approximately 12 by 8 inches. Drizzle oil lightly over garlic and sprinkle with salt and pepper. Fold other side of foil over and seal on all sides to form an airtight pouch. Transfer to a baking sheet and place in oven. Roast until cloves are soft and golden brown, about 1 hour.
Remove from oven and let sit until cool enough to handle. Squeeze each head of garlic, gently pressing with your fingers to expel the soft cloves into a bowl. Stir garlic with a rubber spatula to blend thoroughly.
Cook's Note: Roasted garlic can be refrigerated in an airtight container until needed, up to 2 weeks.