Lemon or Lime Ice Cream

Place the citrus zest and sugar in a food processor. Pulse until the mixture is smooth and the sugar is brightly colored.

Combine the heavy cream, milk, salt, and the citrus-sugar mixture in a small pot. Heat over medium heat for 5 minutes until the sugar dissolves.

Place the egg yolks in a separate mixing bowl and whisk until smooth.

Slowly pour approximately one-third of the hot cream mixture into the egg yolks while whisking constantly to temper the eggs.

Return the tempered yolk mixture to the pot with the remaining cream.

Cook the mixture over medium-low heat, stirring constantly, until the custard thickens enough to coat the back of a spoon, reaching 77°C (170°F).

Remove the pot from the heat and let the custard steep for 30 minutes to infuse the flavor.

Stir in the citrus juice and the remaining zest.

Pour the mixture through a fine-mesh sieve into a bowl to remove the zest and any solids.

Cover the bowl and refrigerate for at least 4 hours, or overnight, until completely chilled.

Process the cold custard in an ice cream maker according to the manufacturer's instructions. Serve immediately or freeze until firm.