Place scapes and walnuts in a food processor and pulse to break them up.
With the motor running, slowly drizzle in the olive oil until the mixture is smooth. Add the Parmesan, season with salt and pepper, and pulse a few times to mix.
Use immediately or store in an airtight container in the fridge.
Recipe by Flying on Jess Fuel at https://www.jessfuel.com/harvest-fridays-garlic-scape-pesto/