Garlic ice cream may seem like a weird flavor combination, but it is actually so delicious it's famous! Garlic ice cream has a nice, mild and nutty flavor.
Slice top of garlic head off and set cut side up on a double layer of aluminum foil. Drizzle with oil and 2 tbsp. water; wrap into a tight package.
Bake until cloves are very tender, about an hour; let cool slightly. Squeeze garlic cloves from bulb into a blender; set aside.
Whisk sugar, salt, and yolks in a 4-qt. saucepan until pale yellow, about 2 minutes. Stir in milk and cream; cook over medium, stirring occasionally, until thickened and mixture coats the back of a spoon, about 10 minutes.
Transfer 1 cup custard to blender with garlic and the vanilla; purée until smooth and stir into remaining custard. Cover custard with plastic wrap, pressing it against the surface of the custard; chill.
Pour into an ice cream maker and freeze according to manufacturer's instructions. Transfer to an airtight container and seal; freeze until set, about 4 hours.