01 - Combine whole milk, heavy cream, granulated sugar, and sea salt in a medium saucepan. Warm over medium heat, stirring until sugar dissolves without boiling.
02 - Whisk egg yolks in a separate bowl. Gradually add about 1 cup of the warm milk mixture to the yolks while whisking constantly to temper.
03 - Pour the tempered yolks back into the saucepan with the remaining milk mixture, stirring to combine.
04 - Cook over low heat, stirring continuously with a wooden spoon until the custard thickens enough to coat the back of the spoon, reaching about 170°F (77°C). Avoid boiling.
05 - Remove from heat and strain through a fine-mesh sieve into a clean bowl to eliminate any curdled bits.
06 - Allow custard to cool to room temperature, then whisk in extra virgin olive oil and vanilla extract (if used) until smooth and fully emulsified.
07 - Cover and refrigerate the mixture for a minimum of 4 hours, preferably overnight.
08 - Process the chilled custard in an ice cream maker following manufacturer’s instructions until thick and creamy.
09 - Transfer the churned ice cream to a freezer-safe container and freeze for at least 2 hours prior to serving.