Summer Squash and Red Quinoa Salad with Walnuts

INGREDIENTS

• 6 tablespoons extra-virgin olive oil
• Freshly ground black pepper
• 1 teaspoon finely grated lemon zest
• 2 tablespoons finely grated Parmesan plus 1/4 cup shaved with a peeler
• 2 teaspoons kosher salt plus more for seasoning
• 1 tablespoon Sherry vinegar
• 1 pound assorted summer squash
• 2 tablespoons fresh lemon juice
• 1/2 cup red or other quinoa, rinsed in a fine-mesh sieve, drained
• 1/4 cup fresh basil leaves, torn
• 1/2 cup flat-leaf parsley leaves
• 1/2 cup walnuts, toasted