Preheat the oven to 400F. Place the garlic heads on 3 pieces of aluminum foil and drizzle each with one tablespoon olive oil.
Wrap the aluminum foils around each garlic head and roast in the oven for one hour until the cloves are soft. Let them cool for 20-30 minutes.
Once cool, squeeze the cloves out and put them in a bowl. Mash them using a fork. Add in sour cream and mix well.
Add in Mayonnaise, dried rosemary, dried thyme, chopped parsley, salt, ground black pepper and lemon juice. Mix well using a spoon.
Chill in the fridge for at least an hour before serving.