Place the cream, milk and 1/2 cup sugar into a large saucepan, whisk and then heat over medium heat until the sugar is disolved
Whisk the remaining 1/4 cup sugar, egg yolks and passionfruit together in a large mixing bowl until light and well combined
Slowly add half of the milk mixture to the yolk mixture, whisking the entire time
Slowly add the warmed yolk mixture into the remaining milk in the large saucepan
Over very low heat, whisk until thickened and the mixture coats the back of a spoon; about 5 minutes. DO NOT STOP WHISKING or you will have scrambled eggs
Place the custard mixture into a glass bowl, cover with plastic and place in the refrigerator to cool, preferably overnight
When cooled, add to ice cream maker and churn as per your ice cream makers instructions
Notes
based on a recipe at: http://chezus.com/2014/05/25/passion-fruit-ice-cream/