Place the egg yolk in a mixing bowl.
Add minced garlic and lemon juice to the bowl.
Whisk the mixture until well combined.
Slowly drizzle in the olive oil while continuously whisking.
Continue whisking until the aioli thickens and becomes creamy.
Add salt and pepper to taste.
If too thick, whisk in a few drops of water or lemon juice.
Transfer the aioli to a serving dish.
Cover and refrigerate for at least 30 minutes before serving.