Preheat Oven:
Preheat your oven to 350°F (175°C). Grease a 9x13 inch baking dish.
Prepare Stuffing:
Prepare the stuffing mix according to the package directions. Set aside.
Sauté Vegetables:
In a large skillet, melt the butter over medium heat. Add the chopped onion and celery, and sauté until they are soft and translucent.
Combine Ingredients:
In a large mixing bowl, combine the shredded rotisserie chicken, cream of chicken soup, cream of mushroom soup, chicken broth, milk, sour cream, sautéed onions and celery, and thawed peas and carrots. Mix until well combined. Season with salt and pepper to taste.
Assemble Casserole:
Pour the chicken mixture into the prepared baking dish. Spread it out evenly. Spoon the prepared stuffing evenly over the top of the chicken mixture.
Bake:
Bake in the preheated oven for 30-35 minutes, or until the casserole is bubbly and the stuffing is golden brown.
Serve:
Let the casserole cool for a few minutes before serving. Enjoy your comforting and delicious Rotisserie Chicken and Stuffing Casserole!