Preheat your oven to 350°F (175°C).

Cook the pasta according to package instructions until al dente; then drain and set aside.

In a large skillet, melt the butter over medium heat. Add the chopped onions and minced garlic, sautéing until softened and fragrant.

Toss in the sliced mushrooms, cooking until they're tender.

In a spacious bowl, combine the cooked pasta, shredded chicken, and the sautéed vegetable mix. Stir in the sour cream, chicken broth, Parmesan cheese, salt, black pepper, and paprika. Mix everything well.

Transfer this creamy mixture into a greased baking dish, ensuring it’s spread evenly.

Sprinkle the top with shredded mozzarella cheese and, if you like a crunchy topping, add some bread crumbs.

Bake for 25 to 30 minutes, or until the top is golden and bubbly.

Allow the dish to cool for a few minutes before serving to ensure it holds together nicely.