Discard the papery outer layer of the whole head of garlic.
Cut the top off head.
Drizzle with olive oil.
Wrap the garlic in aluminum foil.
Bake in preheated oven for 40-45 minutes or until tender.
Remove from the oven and allow to cool completely.
In a heatproof bowl, beat the egg yolks with sugar and set aside.
Place the milk, heavy cream, vanilla extract and pinch of salt in a pot and bring to boil over medium heat.
Remove from the heat and gradually pour it into the egg yolk mixture, whisking constantly.
Place the bowl over a pot filled with simmering water.
Stir the custard gently with a spatula until it thickens enough to coat the back of a spoon, about 15 minutes (mixture should be 185 °F).
Remove from the heat.
Add the custard to a blender.
Squeeze out roasted garlic cloves into a blender.
Blend until smooth.
Transfer in a refrigerator and chill for at least 4 hours, or overnight.
Pour the mixture into an ice cream maker and freeze according to the manufacturer’s instructions or pour the mixture into a container and freeze until set.