In a food processor, pulse sage and parsley leaves, garlic, walnuts, lemon juice and zest, salt and pepper until smooth.
With motor running, slowly pour in olive oil.
Turn off motor and stir in Parmesan cheese
Store in the fridge for up to a week
Notes
Toast walnuts in a skillet over medium-low heat until fragrant, about 5 minutes, shaking the pan every couple of minutes. Remove from heat and allow to cool before using in the recipe.