Rinse a medium pot with cold water before adding the liquid, this keeps the milk from burning and sticking to the bottom of the pot.
To the pot add ⅓ cup + 1 tablespoon of milk (90 grams), the cream and sugar, bring to a boil, stirring occasionally.
In a medium bowl whisk together the egg, corn starch and remaining milk.
Add half the boiling milk mixture to the egg mixture and whisk to combine, then pour into the remaining milk mixture in the pot, with the vanilla and salt. Bring it back to a boil and stir constantly until thickened, it won't take long to thicken. Pour into a clean bowl, cover with plastic wrap, make sure it touches the top of cream (this keeps the cream from developing a skin). Refrigerate until cooled completely, approximately 2 hours. Enjoy!