Start by roasting the head of garlic. To do this you will heat the oven to 400ºF. Cut off the top on the head of garlic (it is the part that points up). Peel off any excess skin.
Place the head of garlic in the middle of a piece of foil. The foil needs to be large enough to cover the entire head plus some. An 8"x8" piece should work.
Drizzle the avocado oil on top of the garlic head. Firmly cover the garlic all over with the foil to form a ball. Place the garlic on a baking sheet and roast for 40 minutes. After 40 minutes remove the pan from the oven and let it cool for about 10 minutes before removing the foil from the garlic.
Remove the foil and when the garlic is cool enough to handle, remove all of the roasted cloves from the head. Add them to your blender or food processor.
You will now add the mayo, lemon juice, salt, and pepper with the garlic cloves in your blender or food processor. Turn it onto medium speed for at least 30 seconds, or until the garlic is minced in and all ingredients are well blended. If you are not ready to use the aoli, you can refrigerate it for up to 2 days.