Zest of 1 lemon [ you'll use the juice in the next step]
6lemons [may take more]
2 tablespoons vodka [optional, but it prevents iciness in the final result]
1cuphalf and half
Blueberry Sauce Ingredients
1cupfresh blueberries
1lime [juice and zest]
2tablespoonsgranulated sugar
1teaspoonwater
Pinchkosher salt
1teaspoonvodka
Instructions
Make the sherbet base
Juice the lemons, taking care not to get any seeds in there. You need one cup of fresh lemon juice.
Using a 3 quart heavy sauce pan, mix together the water, sugar, cornstarch, salt and lemon zest. Stir constantly over medium heat, until the sugar is dissolved, and the mixtrue is slightly thickened. You want a light simmer for this or the cornstarch won't incorporate.
Stir in the lemon juice and place the mixture in the refrigerator to cool completely - about 90 minutes or so.
Make the bluberry sauce
Place the blueberries, lime juice and zest, water, sugar and salt in a small saucepan.
Watch closely and stir frequently while the mixture comes to a simmer, the sugar dissolves, and the blueberries break down. Place this mixture in the refrigerator to cool.
Freeze the sherbet
Remove the sherbet base from the refrigerator, and gently stir in the half and half and the vodka.
Assemble the ice cream maker, and push the start button. If you're using an ice cream maker like the one linked above, it's important that the machine is running before adding the liquid. Pour in the sherbet base.
Run the ice cream maker for about 25 to 30 minutes, until the sherbet has expanded somewhat and is looking frozen and creamy.
Combine the sherbet and blueberry sauce
When the sherbet is nearly frozen, remove the blueberry mixture from the refrigerator, and stir in the vodka.
Work quickly, once the sherbet is done or you will have trouble getting it out of the ice cream maker. Put 1/3 of the sherbet in a container. Immediately, spread about 1/3 of the blueberry sauce over the sherbet. repeat this 2 more times, until all of the sherbet and blueberry sauce are layered in the container.
Use a table knife or large spoon to gently stir back and forth to create a swirl pattern in the sherbet. Cut a piece of parchment paper to fit on the surface of the sherbet, and press down firmly to prevent ice crystals from forming,
Place the container in the freezer for at least 2 hours, though 4 hours is better.
Notes
The sherbet will keep in the freezer for up to a month. Be sure to always press parchment paper or plastic wrap on the surface of the sherbet when returning to freezer. This will prevent freezer burn, which can otherwise occur rather quickly on the top of homemade ice cream.