01 - In a medium saucepan, gently heat the milk and heavy cream over medium heat until steaming but not boiling.
02 - In a bowl, whisk together egg yolks, granulated sugar, vanilla extract, and salt until pale and creamy.
03 - Slowly pour the warm milk mixture into the egg yolks while whisking constantly to avoid curdling.
04 - Transfer the combined mixture back to the saucepan and cook over low heat, stirring continuously with a wooden spoon or spatula until it thickens enough to coat the back of the spoon, approximately 8 to 10 minutes. Avoid boiling.
05 - Remove from heat and strain through a fine mesh sieve into a clean bowl to achieve a smooth texture.
06 - Serve immediately warm or cover with plastic wrap and refrigerate for at least 2 hours to serve chilled.