Add all ingredients except olive oil to a food processor. Mix until a loose paste forms.
While the food processor is running, drizzle in olive oil. Start with 4 tbsp and add more as desired. You can also add some water to help make a smoother paste. (I like to keep my pesto somewhat thick, then when I make pasta I use some of the pasta water to thin it out.)
Taste and add more salt/pepper/lemon juice as desired.
Store in an air tight container in the fridge for up to 1 week.
Video
Notes
Basil: You can replace up to 1 cup basil with 1 cup arugula, spinach, or kale.Nuts/Seeds: You can mix and match pine nuts, walnuts, almonds, cashews, pistachios, sunflower seeds, pumpkin seeds, and hemp seeds.