Place 1/2 cup walnuts, 1 clove garlic and 1/2 cup Parmesan cheese into the bowl of a food processor and process until all ingredients are blended together.
Add 3 cups baby arugula and 1 cup basil - pulse until the leaves have broken up.
Gradually add 1/2 cup extra virgin olive oil while the processing.
Adjust consistency by adding water.
Notes
Store leftover pesto sauce in the refrigerator for up to three days. Freeze pesto for up to 6 months in a freezer-safe container.See the article above for recipe tips, variations and more.