Preparation

1. In a medium saucepan set over medium-low heat, stir together the milk and heavy cream. Bring the mixture just to a boil. Turn heat off and add the orange zest; let mixture steep for 30 to 60 minutes. After steeping, add half of the sugar and salt and gradually return the mixture just to a boil over medium-low heat.
2. While the milk /cream mixture is reheating, combine the yolks and remaining sugar in a medium bowl. Using a hand mixer on low speed or a whisk, beat until mixture is pale and thick.
3. Once the milk /cream mixture has come to a slight boil, whisk about ¹∕³of the hot mixture into the yolk/sugar mixture. Add another ¹∕³of the mixture, then return the combined mixture to the saucepan. Using a wooden spoon, stir the mixture constantly over the low heat until it thickens slightly and coats the back of the spoon. This mixture must NOT boil or the yolks will overcook – the process should only take a few minutes.
4. Stir in the vanilla and Grand Marnier and pour the mixture through a fine mesh strainer (discard the orange zest); bring to room temperature. Cover and refrigerate at least 2 hours, or overnight. Whisk mixture again before pouring into the ice cream maker.
5. Pour the mixture into the mixing bowl of the Cuisinart® Ice Cream and Gelato Maker fitted with the ice cream paddle. Turn unit on, set Timer and press Start. Let mix until thickened, about 40 minutes. The ice cream will have a soft, creamy texture. If a firmer consistency is desired, transfer to an airtight container and place in freezer for about 2 hours. Remove from freezer about 15 minutes before serving.