Chicken Zucchini Casserole

Ingredients

• buttery cooking spray
• 1 pound chicken breast, cooked and cubed
• 1 cup onion, chopped
• 3 cups diced zucchini
• 1/2 cup carrots, shredded
• 1 package (6 oz.) stuffing mix
• 1/2 cup reduced fat butter
• 1 can (10 1/2 oz.) reduced fat condensed cream of chicken soup, undiluted
• 3/4 cup fat free sour cream