Preheat the oven to 400°F and spray a 9×13-inch casserole dish with non-stick spray.

Prepare the stuffing mix per box directions: combine hot water and stuffing in a bowl and microwave on high for 5–6 minutes. Optional: stir in 2–4 Tbsp butter for extra richness. Cover and let it steam while you assemble.

Spread 2 cups shredded chicken in an even layer across the casserole dish. Season evenly with salt, pepper, and Mrs. Dash Onion & Herb Seasoning.

In a separate bowl, whisk together both cans of condensed cream of chicken soup and 1/4 cup milk until smooth. Pour this mixture over the chicken in the dish.

Spoon the prepared stuffing over the soup-covered chicken, spreading it into an even layer.

Cover the casserole tightly with aluminum foil. Bake for 20 minutes covered.

Remove the foil and bake an additional 10 minutes to brown and crisp the stuffing top.

Let the casserole rest on a wire rack for 5–10 minutes before serving to let the filling set.