Wild Rice Chicken Casserole

• 1 1/2 seasoned bread stuffing dry mix
• 550 gr chicken
• 140 ml waterchestnuts
• 240 ml chicken broth
• 110 gr butter
• 100 gr celery (chopped)
• 45 ml soy sauce
• 30 gr onion (chopped)
• 1 package wild rice
• 1 package cream of chicken soup