Makes 1 1/4 cups
Combine mint, parsley, basil, chives, and oregano in a food processor and process until finely chopped. Add walnuts, garlic, Parmesan, and lemon zest and pulse to combine. With the machine running, add oil in a steady stream. Add lemon juice, salt, and pepper, and pulse to combine. Transfer pesto to a nonreactive bowl and cover it with plastic wrap, pressing wrap so that it sits directly on top of pesto. Set aside until ready to use.
Cook's Note: The pesto sauce can be made up to 2 days in advance and refrigerated until ready to use. If you choose to make it ahead of time, cover the surface of the sauce with a thin film of olive oil to keep the sauce from darkening. Return it to room temperature before serving.