Preheat oven to 325°F and get out a loaf pan, cake pan, or other oven safe small pan to set the bulbs in.
Peel all but the last layers of paper from the outside of the bulbs.
Find the point on the tips of the garlic where most of the cloves come together and use a sharp knife to cut the tip off from that point, exposing the cloves.
Use a small knife to carefully trim the tips off of any remaining cloves.
Set each bulb on a small square of foil and drizzle with a tablespoon of oil each. Make sure all the exposed clove tips are coated in oil, as is the entire outside of the bulb. This is most easily done by hand.
Wrap the bulb and set it in the pan, cut side up. If needed, use small balls of foil to stand them upright.
Roast for 1 hour.
Remove from the oven and let cool ten minutes. Then remove the bulbs and peel back the foil. Allow to cool until you can handle it comfortably.
Peel back the papers on each garlic clove and place the roasted clove on a freezer safe tray or baking sheet. Repeat until you've removed all the cloves from the bulbs. *
Freeze for 1 hour, or until cloves are solid. Transfer to a freezer safe bowl and store for up to 3 months.
*Alternatively you can squeeze the cloves out by gently pressing at the base of each clove. This usually leads to more of a garlic paste than a true clove.