Preheat oven to 375 degrees F. Heat chicken broth and butter in a medium saucepan until boiling. Add the stove top stuffing mix and toss to moisten evenly. Remove from heat and cover. Let sit for 5 minutes.
3 cups chicken broth, ½ cup salted butter, 2 (6-ounce) packages stuffing mix
Melt 2 Tablespoons of butter in a large skillet over medium heat. Add the onion and celery, then saute until soft and translucent, about 5-7 minutes.
2 tablespoons salted butter, 1 medium onion,, 3 celery stalks
Add mushrooms and season with the garlic powder and pepper. Continue to cook, stirring occasionally, until the mushrooms are browned.
8 ounces mushrooms,, ½ teaspoon garlic powder, ½ teaspoon black pepper
In a large bowl, whisk together the cream of chicken soup, sour cream, chicken broth, and worcestershire sauce.
1 (10.5-ounce) can cream of chicken soup, 1 cup sour cream, ½ cup chicken broth, 1 tablespoon worcestershire sauce
Add the shredded chicken, frozen mixed vegetables, and sauteed vegetables to the chicken soup mixture and stir well until combined. Spread the mixture into a 9x13-inch casserole dish or baking dish.
3 cups shredded, cooked chicken, 1 (12-ounce) bag frozen mixed vegetables,
Place cheese slices over the top of the chicken mixture.
8 slices shredded cheddar or provolone cheese
Spread the stuffing mixture over the top of the casserole.
Bake for 40 minutes until heated through and stuffing is lightly browned on top.