Prep the lemons. You will need 2 whole lemons and the juice from a third lemon for this recipe. Wash the 3 lemons thoroughly. Juice one lemon, save the juice, and discard the lemon rind. Trim off the bumpy ends of the remaining two lemons, then cut each in half the long way, and slice each half into quarters. Remove the seeds and trim out the thick white membrane core from each segment, and discard.
Puree the lemons. In a high-powered blender, add the 2 diced lemons, the lemon juice, pine nuts, garlic, Parmigiano-Reggiano, salt, and pepper and blend on medium speed until the lemons have broken down and begin to look smooth, 30 seconds to 1 minute.
Add the olive oil. With the blender running on low speed, slowly stream in the olive oil until the mixture is smooth and creamy. Increase the speed and blend for an additional 30 seconds.
Serve or store. Use immediately or store in an airtight container in the refrigerator for up to 3 days.
