Preheat your oven to 350°F (175°C).

In a large pot, bring salted water to a boil and add the spaghetti or linguine. Cook according to the package instructions until al dente. Drain and set aside.

In a large skillet, heat the olive oil over medium heat. Add the onions and mushrooms, sautéing until they’re tender and fragrant, about 5 minutes.

In a separate bowl, combine the chicken broth, sour cream, milk, and half of the Parmesan cheese. Stir in the garlic powder, salt, pepper, and paprika.

In a large bowl, combine the cooked pasta, sautéed veggies, shredded chicken, and frozen peas. Pour the creamy sauce over the mixture and gently fold everything together.

Spread the mixture evenly into a greased 9×13-inch baking dish. Sprinkle the remaining Parmesan cheese and the cheddar cheese on top.

Bake for 25-30 minutes or until bubbly and golden on top.

Once out of the oven, sprinkle with fresh parsley if desired. Scoop onto plates and serve.