Preheat Oven to 350˚F.
Cook linguine according to package directions in a large pot of salted water until al dente.
In a large bowl, toss shredded rotisserie chicken with paprika, onion powder, and garlic powder. Set aside.
In a large dutch oven, or thick bottomed pot over medium high heat, add 2 tablespoons olive oil, and add in mushrooms. Saute 3-5 minutes until softened.
Add diced onions and cook until onions are soft and golden, another 5-7 min.
Add minced garlic and sauté 1-2 min until fragrant.
Place all the cooked mushrooms and onions into the bowl with the shredded rotisserie chicken.
Then, using the same dutch oven, melt 4 Tbsp butter and gradually whisk the flour into the butter, cooking until golden brown, about 1-2 minutes.
Continuing to whisk, gradually add 2 1/2 cups chicken broth, 1 Tbsp lemon juice, 1 tsp salt, 1/4 tsp pepper and whisk until smooth.
Once smooth, add the half and half and the sour cream, bring to a simmer.
Taste the sauce, and season with salt and pepper to preference.
Add the chicken and mushroom mixture back into the pot, along with the parsley and linguine. Stir to incorporate.
Pour into a greased baking dish, and cover with shredded mozzarella. Cover with foil, and bake at 350˚F for 25-30 min
Remove foil and continue baking for 10 mins.
Garnish with additional fresh parsley, and serve.