To make the chocolate chunks: In a medium stainless steel bowl set in a skillet of not quite simmering water, melt the chocolate (if using) with the water, stirring frequently (see note below). Remove from the heat and pour the mixture onto a piece of parchment paper or foil. Spread into a thin, even layer on a parchment-lined baking sheet.
Put the baking sheet in the freezer and freeze until firm. Chop the chocolate into bits or shards and return them to the freezer until needed.
NOTE: The higher the cacao, the more water will be needed to prevent the chocolate mixture from “seizing.” Start with the 2 tablespoons of water for milk chocolate or dark chocolate with up 60% cacao. Work by eye: Once the chocolate is melted, stir in a few extra drops or teaspoons of warm water, as necessary, to make a smooth, fluid mixture—if it’s stiff or curdled, add water and stir until smooth. For 66% to 72% chocolate, at least an extra tablespoon of water will be needed.
Combine the cream and mint and refrigerate for at least 8 hours and no longer than 10 hours.
Strain the cream into a medium saucepan, pressing on the mint to extract as much liquid as you can; discard the mint. (If you are not ready to make the ice cream immediately, just refrigerate the strained cream until you are.)
Add the milk, sugar, and salt to the cream and bring to a simmer over medium heat. Set a fine mesh strainer over a medium bowl near the stove for the finished ice cream base.
In another medium bowl, whisk the egg yolks just to combine them.
Add the hot cream in a thin stream, whisking constantly. Return the mixture to the pan and cook over medium-low heat, stirring constantly with a heatproof Silicone spatula—sweeping the bottom, sides, and corners of the pot— until the mixture is slightly thickened and registers between 175º and 180º F. The mixture should be slightly thickened, but even if not, remove it from the heat before it exceeds 180º (see note below).
Strain the mixture into the clean bowl. Let cool, then refrigerate, covered, until thoroughly chilled.
Freeze according to your ice cream maker's instructions, adding the chocolate chunks at the end.
NOTE: If your burner heat is too high, the mixture may reach 180º F before it has a chance to thicken, which is not a disaster, but not ideal. Regardless, if the temperature exceeds 180º F, there is a risk of scrambling the eggs. Bottom line: Cooking lower and slower is better than hotter and faster.
My career was sparked by a single bite of a chocolate truffle, made by my Paris landlady in 1972. I returned home to open this country’s first chocolate bakery and dessert shop, Cocolat, and I am often “blamed” for introducing chocolate truffles to America. Today I am the James Beard Foundation and IACP award-winning author of ten cookbooks, teach a chocolate dessert class on Craftsy.com, and work with some of the world’s best chocolate companies. In 2018, I won the IACP Award for Best Food-Focused Column (this one!).