Tarragon Chicken Salad

Ingredients

• 2 cups diced cooked chicken
• 1 small tart apple, cored and diced (about 1 1/2 cups)
• 1/3 cup diced celery
• 1/4 cup diced red onion
• 3/4 cup mayonnaise
• 1 tablespoon fresh lemon juice
• 2 tablespoons chopped fresh tarragon leaves
• 1 tablespoon chopped fresh parsley leaves
• 1 tablespoon chopped fresh chives
• 1/4 teaspoon kosher salt, or more to taste
• 1/4 teaspoon freshly ground black pepper
• 1/3 cup roasted and lightly salted cashews, walnuts, or pecans, roughly chopped
• 4 cups arugula, washed and dried
• Olive oil, for dressing arugula