Place garlic and salt in a food processor fitted with a metal blade, or in a blender. Pulse for 2 seconds. Add the egg yolk and lemon juice, and pulse on and off until blended. Turn on and begin adding the olive oil (pure first, then extra-virgin) in a thin stream. If it becomes too thick, thin it out with some room-temperature water and continue adding oil until you've used it all. Finish with pepper and (if necessary) a bit more salt.
The reason for using 2/3 pure olive oil is to keep the flavor of the oil from becoming overpowering. This is a perfect example of how by using a fully-flavored extra virgin oil you can use much less, thereby saving money and getting better flavor.
Consumption of raw or undercooked eggs, shellfish and meat may increase the risk of foodborne illness.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.