Homemade Noma-Style Elderflower Ice Cream

In a medium saucepan, combine heavy cream, whole milk, 1/2 cup (100g) of the granulated sugar, and the pinch of salt. Heat over medium heat, stirring occasionally, until the mixture just begins to simmer and steam. Do not let it boil.

While the cream mixture heats, whisk the 4 egg yolks and the remaining 1/4 cup (50g) of granulated sugar in a separate bowl until the mixture is pale yellow and thick.

Temper the egg yolks: Slowly ladle about 1/2 cup of the hot cream mixture into the whisked egg yolks, whisking constantly to prevent the eggs from scrambling. Gradually add another 1/2 cup, continuing to whisk. This slowly raises the temperature of the yolks.

Pour the tempered egg yolk mixture back into the saucepan with the remaining hot cream. Cook over medium-low heat, stirring continuously with a rubber spatula, until the custard thickens enough to coat the back of a spoon (170-175°F / 77-79°C). Do not boil the custard, as this can curdle the eggs.

Remove the custard from the heat. Stir in the elderflower cordial (or syrup), vanilla extract (if using), and lemon zest (if using).

Strain the custard through a fine-mesh sieve into a clean bowl to remove any potential cooked egg bits or zest. This ensures a smooth ice cream texture.

Cover the surface of the custard directly with plastic wrap to prevent a skin from forming. Chill the mixture in the refrigerator for at least 4 hours, or preferably overnight, until it is thoroughly cold.

Once the base is completely chilled, churn it in an ice cream maker according to the manufacturer's instructions. This typically takes 20-25 minutes, until the ice cream reaches a soft-serve consistency.

Transfer the freshly churned ice cream to an airtight container. Freeze for at least 2-4 hours, or until firm, before serving.