In a medium saucepan, heat heavy cream and whole milk until steaming but not boiling, about 5 minutes. In a mixing bowl, whisk together egg yolks and granulated sugar until pale. Slowly pour the hot cream mixture into the yolks while whisking.

Return the combined mixture to the saucepan and cook over medium-low heat, stirring constantly until thickened and reaches 175°F, about 10-15 minutes. Strain through a fine mesh sieve into a bowl.

Stir in fresh lemon juice, lemon zest, vanilla extract, and salt into the strained custard. Allow to cool to room temperature.

To chill quickly, fill a bowl with ice water, then place your bowl of lemon custard on top. Stir occasionally for about 10 minutes, then cover and refrigerate for at least 4 hours or overnight.

Transfer the custard to your ice cream maker and churn until soft-serve consistency, about 20-25 minutes.

Transfer to an airtight container, press parchment paper on the surface, and freeze for 4-6 hours until firm.