This recipe comes originally from Nigella Lawson. I’ve tinkered with it a bit by adding lemon zest to both the ice cream and the sauce as I think it gives an extra brightness and edge to both.

Makes about 1 quart

FOR THE ICE CREAM
3/4 cup whole milk
3/4 cup sugar
4 ounces cream cheese, room temperature
½ teaspoon pure vanilla extract
1 large egg, room temperature
1½ cups heavy cream, lightly whipped
Juice of half a lemon
½ teaspoon freshly grated lemon zest

FOR THE BLUEBERRY SYRUP
2 cups fresh or thawed frozen blueberries
1½ cups sugar
2/3 cup water
½ teaspoon freshly grated lemon zest
2 teaspoons freshly squeezed lemon juice

Heat the milk in a pan, and while it’s getting warm, beat together the sugar, cream cheese, vanilla and egg in the bowl of a freestanding mixer with a paddle attachment until smooth. When the milk comes to just below the boil, whisk the cream cheese mixture while slowly drizzling the milk in a thin and continuous stream so the egg is gradually warmed up. Return everything to the saucepan and cook while stirring with a wooden spoon. Make sure that you are constantly scraping the spoon across the bottom of the pan so the custard does not scorch. The custard is done when it has thickened slightly and can evenly coat the back of the spoon and when you run your finger along the back of the spoon and it holds the “line.” Do not let the mixture come to a boil, or it may curdle.

Strain the custard into a metal bowl through a fine sieve to remove any bits of egg. Nestle the bowl of custard into a large bowl of ice water to cool more quickly. I do this because I’m incredibly impatient, but you could just put the whole thing in the fridge to cool. Add the lemon zest and juice and whisk in the slightly beaten cream, stirring occasionally until mixture is cold, about 20 minutes.

Transfer the custard to an ice cream machine and freeze according to the manufacturer's instructions. Put the finished ice cream in a storage container and freeze until firm.

To make the blueberry syrup, combine all the ingredients in a medium saucepan and bring to a boil. Lower the heat and simmer until thickened to desired consistency. Remove from the heat and let cool to room temperature before serving. (If thinner syrup is desired, strain through a fine mesh strainer while still hot.