Step 1

In a medium-sized saucepan, bring the half-and-half and vanilla to a gentle simmer over medium heat, stirring occasionally to prevent a skin from forming on top.

Step 2

Meanwhile, vigorously whisk together the yolks, sugar and salt for around 30 seconds, until the yolks are creamy and thick, which means the sugar has dissolved (this is also known as the ribbon stage).

Step 3

Once the cream reaches a gentle simmer, slowly pour or ladle it into the yolks while whisking. Turn the heat to low and return the mixture to the saucepan, scraping everything from the bowl with a spatula.

Step 4

Using a spatula or wood spoon, stir the mixture for several minutes in a figure 8 motion, until the liquid has thickened slightly, approximately 5 minutes. If you want to use a thermometer, the temperature should read 165 degrees F.

Step 5

Transfer to a medium-sized bowl. Whisk in the olive oil (it might look separated at first, but will combine with the other ingredients), then cover with plastic wrap, pressing the plastic directly against the liquid to prevent a skin from forming.

Step 6

Chill for around 4 hours (see notes), and then prepare in your ice cream maker according to manufacturer instructions.