In a medium saucepan, gently heat the whipping cream, milk, mint leaves and 1/2 cup of the sugar over medium heat, stirring constantly, until temperature reaches 165F or about five minutes and almost simmering. Remove from heat and cover. Let stand for 15 minutes.

In a medium bowl whisk 4 egg yolks with 1/2 cup of sugar and salt.

Slowly add the warm mixture in a stream, while whisking constantly, to egg mixture.

Pour contents of bowl back into saucepan and warm over medium-low heat until mixture thickens and becomes a custard. It should register 175F on a thermometer but if you don't have one, it should easily coat the back of a wood spoon.

Pour mixture through a fine mesh sieve, to remove mint leaves and any lumps that formed, into a heat proof bowl. Stir in green food colouring here if you wish. Let cool for 10 minutes then place a piece of plastic wrap directly on top of mixture to prevent a skin from forming and cool in refrigerator for at least four hours. I often let it cool overnight.

Pour your mixture into your ice cream machine and churn until thickened and starting to freeze. Add mini chocolate chips just before turning machine off to distribute throughout ice cream.

Scrape into freezer proof dish and freeze immediately. Will last 3 months in freezer but it will never last that long.