Combine milk, sugar and egg yolks in the top of a double boiler and whisk together over simmering water. Add chopped mint and continue to stir constantly until the mixture is thickened, about 5-10 minutes. Remove from heat and combine with heavy cream and refrigerate until completely cooled.
Strain mixture and discard mint. Add extract and food coloring, if using, and stir together. Process in an ice cream machine according to the manufacturer's directions. After removing the soft service ice cream from the machine, stir in the chocolate chips and freeze until firm.
Recipe by Cooking With MicheleĀ® at https://cookingwithmichele.com/2011/07/mint-chocolate-chip-ice-cream/