Whisk yolks and sugar in a medium bowl until pale in colour then set aside.
Add milk and cream to a large saucepan and heat, stirring occasionally, on medium heat until simmering.
Remove saucepan from heat and scoop out a cup of the heated milk. Whisk the milk into the yolks until combined then slowly stir them back into the saucepan of milk.
Resume heating the milk on a low-medium heat until it thickens. When it coats the back of a spoon remove from heat and stir in the vanilla, sriracha and salt.
Pour into an airtight container and refrigerate for at least 3 hours until chilled.
Add to an ice cream machine and churn as per manufacturer's instructions. Scoop into a container and freeze until hardened.
