Whisk the egg yolks with sugar until pale yellow and thick.
Bring the milk to a boil in a medium saucepan over medium-high heat, then switch off the heat.
Slowly pour the milk into the egg mixture, stirring vigorously off the heat to avoid scrambling. Add the mixture back to the saucepan and return to the heat.
Whisk the mixture continuously until the mixture thickens and coats the back of a spoon (you should be able to draw a line through it with your finger) and take off the heat.
Add the vanilla bean paste/extract.
Cover with plastic wrap (let the plastic wrap touch the surface of the custard) and place in the fridge until completely cooled.
Put in the ice cream maker and churn according to manufacturer’s instructions and freeze until ready to serve.
Take out of the freezer about 5 minutes before serving to soften.
