By Madeleine Dee
2. Drain the arugula and add it to your blender or food processor with the Parmesan, lemon, salt, pepper, walnuts, and garlic. Start to puree while slowly drizzling in the olive oil. When finished, the pesto will be smooth and a beautiful shade of green. Adjust the seasoning as you please. Enjoy immediately or store in an airtight container for later!