Preheat the oven to 350 degrees.

Pull the garlic heads apart. Combine the garlic cloves with the olive oil in a baking pan, spreading them out to form a single layer.

Place them in the preheated oven and roast them for about 30 minutes, or until the garlic is very tender.

Remove them from the oven and allow to cool.

When the garlic is cool enough to handle, using your fingertips, push the soft garlic pulp from the skins. Place the pulp in the small bowl of a food processor fitted with the metal blade and process to a smooth purée.

Transfer it to a nonreactive container.

Cover and refrigerate it for up to 1 week, or freeze for up to 3 months.