Once the pasta and chicken are done cooking, transfer them to a 9×13-inch casserole dish. Add in the alfredo sauce, the whole jar of sun-dried tomatoes, shredded parmesan, reserved pasta water, garlic paste, chopped basil, paprika, Italian seasonings, salt, pepper, and red pepper flakes.
Toss until all of the ingredients are evenly coated. If it's easier, you can mix all of the ingredients together in a large bowl or in the pot used to cook the pasta before adding it to the baking dish. Shred or crumble the fresh mozzarella and sprinkle it over the top of the pasta. Bake for 20 minutes or until the top of the cheese is melted and bubbly and some spots are starting to brown. Garnish with fresh basil and serve hot.