Oven Method:Preheat the oven to 300°F. Combine all of the ingredients in an oven-proof container and transfer to the oven. Cook for 60 minutes, or a little more if needed, just until the garlic is tender but not browned. Using a slotted spoon, transfer the garlic to a glass jar and pour 1/4 of the cooking oil on top, and reserve the rest of the garlic oil for cooking. Seal and refrigerate for up to 1 month.
Stovetop Method:
Combine all of the ingredients in a medium saucepan and simmer over low heat until the garlic is tender but not browned, about 30-40 minutes. Let cool.
Using a slotted spoon, transfer the garlic to a glass jar and pour 1/4 of the cooking oil on top, and reserve the rest of the garlic oil for cooking. Seal and refrigerate for up to 1 month.