In a medium-sized saucepan, combine the heavy cream and milk. Heat the mixture over medium-low heat until it reaches a gentle simmer. Do not let it boil.

In a separate bowl, whisk together the egg yolks, sugar, and salt until the mixture becomes pale and creamy.

Slowly pour half of the hot cream mixture into the egg yolk mixture, whisking continuously to prevent the eggs from curdling.

Pour the egg yolk mixture back into the saucepan with the remaining cream mixture. Cook over low heat, stirring constantly, until the custard thickens and coats the back of a spoon. This should take about 8-10 minutes.

Remove the saucepan from heat and stir in the lucuma pulp and vanilla extract until well combined.

Allow the mixture to cool completely, then cover and refrigerate for at least 4 hours or overnight to ensure the flavors meld together.

Once chilled, transfer the custard into an ice cream maker and churn according to the manufacturer's instructions until it reaches a soft-serve consistency.

Transfer the ice cream to an airtight container and freeze for an additional 4-6 hours or until firm.