Preheat the oven to 350°F and grease a 9-by-13-inch baking dish.
Cook the linguine until al dente according to the package directions, then drain well.
Combine the butter, cooked turkey, cream of chicken soup, cream of mushroom soup, sour cream, salt, black pepper, garlic powder, chicken broth, and peas in a large bowl.
Add the drained linguine to the turkey mixture and stir until evenly coated.
Transfer the mixture to the prepared baking dish and sprinkle the mozzarella evenly over the top.
Bake for 25 to 30 minutes, until heated through and the cheese is melted and lightly golden.
Garnish with chopped parsley if desired and serve immediately.