Preheat your oven to 350°F (175°C).
In a large mixing bowl, combine the melted butter, cream of chicken soup, sour cream, chicken broth, salt, and black pepper. Stir this mixture until it is well blended.
Add the cooked and chopped chicken to the bowl, mixing gently to coat all the pieces evenly with the creamy sauce.
Now, pour in the cooked linguini and toss it all together until the pasta is fully combined with the sauce.
Transfer this lovely mixture into a 9×13-inch glass baking dish. Make sure it’s evenly spread out!
Sprinkle the shredded mozzarella cheese generously over the top, and then add the grated parmesan cheese to give it that deliciously cheesy topping.
Bake in the preheated oven for 40 minutes. You’ll know it’s ready when the cheese is melted and bubbly at the edges.
Let it cool slightly before serving.