Place fresh basil leaves, peeled garlic, and a pinch of kosher salt into the bowl of your food processor.
Pulse the mixture until the basil is finely chopped and everything is well combined.
Add the freshly grated parmesan and pecorino cheeses to the food processor. Pulse again until everything is evenly mixed.
With the food processor running, slowly pour in the extra virgin olive oil in a steady stream. Continue to process until the pesto reaches a smooth and creamy consistency.
Taste your pesto and add more salt or pepper if needed to suit your preferences.
Notes
Pulse, Don't Blend - Use short pulses on your food processor to avoid over-processing, which can cause the basil to oxidize and turn brown.Dry the Basil Leaves - Make sure your basil leaves are completely dry before processing. Excess water can dilute the pesto and make it less vibrant.Grate Your Own Cheese - Freshly grated parmesan and pecorino have a superior flavor compared to pre-grated versions.