Prep you ingredients by dicing your garlic scares, grating you parmesan-reggiano, and squeezing your lemon.
Combine your garlic scapes, parmesan-regginao, pistachios and lemon juice in a food processor and process at a medium speed until they are roughly chopped. Continue to run the food processor and slowly pour your olive in through the opening of the lid of the food processor. Process until all of the ingredients are very finely chopped and beginning to become smooth. If the pesto seems a little thick add 2-4 Tbsp of water until the desired thickness is achieved.
Finally stir in salt and pepper to taste. For a basic recipe serve on pasta or zucchini noodles.