Sautéed Chicken and Zucchini with Parsley-Chervil Pan Sauce

INGREDIENTS

• 4 (6-ounce) skinless, boneless chicken breast halves
• 1/2 teaspoon salt, divided
• 1/2 teaspoon freshly ground black pepper
• 6 1/2 teaspoons chilled butter, divided
• 2 teaspoons olive oil
• 3 cups (3/4-inch-thick) slices zucchini (about 2 medium)
• 1/2 cup fat-free, lower-sodium chicken broth
• 1/2 teaspoon dried chervil
• 1 teaspoon fresh lemon juice
• 1 tablespoon chopped fresh parsley