1) In the bowl of a stand mixer, beat together the egg yolks and sugar until the yolks lighten in colour and the sugar is completely dissolved. Set aside.
2) In a medium saucepan, over high heat, combine the milk, double cream and nutmeg and bring just to a boil, stirring occasionally. Remove from the heat and gradually temper the hot mixture into the egg and sugar mixture. Then return everything to the pot and cook until the mixture reaches 70C. Remove from the heat, stir in the bourbon, pour into a medium mixing bowl and set in the refrigerator.
3) Chill the mixture in the refrigerator until it reaches a temperature of 4C, approximately 4 to 6 hours.
4) Once chilled, process in an ice cream maker according to the manufacturer's instructions. Serve as is for soft-serve, or place in an airtight container and put in the freezer for 2 to 4 hours for traditional ice cream.