Place garlic bulbs in the baking dish. Pour olive oil over the top each garlic bulb, and enough to just cover the garlic entirely. Add thyme, spreading between the bulbs.
Bake for 1 hour and 15 minutes.
Remove from the oven and allow to cool for 20 minutes.
Squeeze the garlic cloves out of each head of garlic or separate using a fork if you prefer to keep the cloves whole. If using, add salt and pepper to taste.
Store in a mason jar or other air-tight container in the refrigerator for up to 1 month.
Notes
Nutrition is calculated as an estimate, with only 1 cup olive oil remaining in the confit. The oil can be stored in the refrigerator and used in other recipes as well.
Strain the confit from the oil and store in an airtight container in the refrigerator for 1 month.