4 medium zucchini (about 1 1/2 pounds)
2 cups Italian parsley, roughly chopped
2 cups arugula, roughly chopped
1/3 cup shelled pistachios, plus more for garnish
1 large clove garlic, smashed
1/2 cup grated Parmesan, plus more for garnish
2 tablespoons sherry vinegar (see Recipe Notes)
1 tablespoon freshly squeezed lemon juice, plus more to taste
1/2 cup good-quality olive oil
Kosher salt and pepper, to taste
Spiralize the zucchini using a spiralizer, mandoline, or vegetable peeler. Pat the zucchini noodles very dry with paper towels or a kitchen towel and transfer to a large bowl.
Combine the parsley, arugula, pistachios, and garlic in the bowl of a food processor or blender and process until coarsely chopped. Add the Parmesan, vinegar, and lemon juice, and pulse until combined. With the machine running, slowly add the olive oil until the pesto is thick and smooth. Taste and add salt, pepper, and additional lemon juice as needed.
Add the pesto to the bowl with the zucchini noodles and toss until well combined. Taste and adjust seasoning as needed. Garnish with chopped pistachios and grated Parmesan. Serve immediately.
Red wine or balsamic vinegar can be substituted for sherry vinegar.
Pesto will darken and brown very quickly, but will still be tasty and fresh for several days. For best appearance, use it right away. If storing, store it in the smallest container possible and thoroughly press the pesto to eliminate air pockets. Pour a little olive oil over the surface, cover, and refrigerate for up to a week. Pesto can also be frozen for several months.