With your hands, lightly rub each head of garlic to remove any loose papery skin from the garlic.
Slice off about a 1/2 to 3/4 inch off the top of each head of garlic, exposing the garlic cloves.
Add the olive oil to the bottom of a 4 quart slow cooker and then place the heads of garlic face down in the oil.
Cover and cook on LOW for 4 to 5 hours or until the garlic is fully cooked and lightly browned.
Using tongs, carefully remove the hot heads of roasted garlic.
Now your garlic is ready to use in your favorite recipes.
Notes
This recipe is easily adaptable to make more or less roasted garlic as needed. The ratio is 1 head of garlic per teaspoon of olive oil. Just use a smaller or larger Crock-Pot based on how much roasted garlic you wish to make. Each head of garlic should rest flatly on the bottom of the slow cooker. The cooking time should be right around the same time regardless if you are cooking 1 head of garlic or 8.