In a saucepan, heat the milk and add the sugar. Whisk once in a while till the sugar has dissolved
Add the egg yolk, while whisking. Add the heavy whipping cream as well. Keep whisking till the mixture hits 76 degrees C. Remove from heat
Cut the passion fruits in half and scoop the seeds and pulp into a blender
Blend the passion fruits and pour them through a strainer into the saucepan (where the rest of the ingredients are)
Wait till the mixture in the saucepan is at room temperature again
Transfer the mixture to your ice cream maker and freeze according to the instructions for the ice cream machine
Transfer the ice cream to a airtight box and put it in the freezer for at leased 20 min before serving to make sure that it is frozen