Preheat the oven to 250 degrees.

Separate and peel the heads of garlic into cloves.

Add the garlic, herbs, and oil to the baking dish. Cover tightly with aluminum foil.

Roast in the oven for about 2 hours. Start checking the garlic for doneness at 1 hour. Garlic is done when it is golden brown and soft enough to spread.

Remove from oven and allow to cool.

Store in an air-tight container in the refrigerator for up to 2 weeks.