2 ½ tsp mint extract (or alternatively steep ½ cup fresh mint leaves in warm cream. Discard leaves and proceed to step 1.)
1 cup milk
2 cups heavy cream
⅔ cup white sugar
pinch of salt
6 large egg yolks, whisked
8 oz semisweet chocolate, chopped fine, keep in freezer
2 oz dark chocolate, chopped fine, keep in freezer

1. Pour milk and cream into a heavy bottomed saucepan. Add sugar and salt to the mixture. Heat until just steaming, stirring until sugar has dissolved. Remove from heat. Slowly pour the heated milk cream mixture into the egg yolks, whisking constantly so that the egg yolks are tempered by the warm mixture, but not cooked by it. If you are not confident, ladle milk and cream mixture into the yolks while whisking eggs constantly. Do not pour a lot of hot mixture into the eggs since this could lead to scrambled eggs. Scrape the warmed egg yolks back into the saucepan.

2. Return the saucepan to the stove. Stir the mixture constantly over medium heat with a wooden spoon, scraping the bottom as you stir (~10 minutes). Test if the mixture has thickened: coat the back of a wooden spoon with the mixture. Run your finger across. If the coating does not run, your custard is ready and thick enough. Remove from the heat and run it through a sieve. Discard any granules.

3. Add the mint extract and stir thoroughly. Let the mixture cool at room temperature and then chill in the fridge for at least a few hours.

4. Process in ice cream batter in an ice cream maker per manufacturer's directions. If using the KitchenAid ice cream maker attachment, it takes about 20 to 25 minutes. With about 5 minutes remaining, add the chopped chocolate chips in the ice cream maker as well.

5. Transfer to an airtight container and place in the freezer for at least an hour, preferably several hours.