1/2 cup white sugar
1/2 cup rum, or to taste
4 cups milk
1 tablespoon ground nutmeg
Whip eggs, sugar, and rum in high-powered blender on High until a thick custard forms, about 4 minutes.
Pour milk and add nutmeg to the custard; blend on Medium until well-mixed, about 2 minutes. Increase the speed to High for 1 minute.
Chill for 4 hours before serving.