Pour the olive oil into the slow cooker, and add the garlic. Cover and cook on high for 2 hours, until the garlic is tender.
Remove the garlic from the oil, and mash with a fork. Cover and refrigerate for up to three days. (Garlic doesn’t freeze well.) Strain the oil into a jar with an airtight cover, and refrigerate for up to 6 months.
Makes about 3 3/4 cups of garlic oil, in addition to the 1 3/4 cups of roasted garlic