Preheat oven to 425°F. Grease a 13 x 9-inch baking dish or spray with nonstick cooking spray.
In the prepared baking dish (or in a separate large bowl), whisk together the chicken broth, salad dressing, buffalo sauce, chives, parsley, garlic powder, dill, onion powder, and red pepper flakes. Stir in the chicken, uncooked pasta, diced tomatoes, and celery. Make sure that all of the ingredients are evenly distributed in the pan. Cover tightly with aluminum foil and bake for 40 minutes.
Uncover; stir gently with a fork. At this point you should check the pasta to make sure that it is al dente (firm but just about finished cooking). If it’s still too hard, cover the dish and return to the oven until pasta is al dente. Then move on to the next step.
Sprinkle the cheese over the top. Place the dish back in the oven (uncovered), just until the cheese melts, about 5 minutes. Let rest for about 5 minutes.
Garnish with chopped fresh herbs and sliced green onions. Drizzle each serving with additional salad dressing and buffalo sauce.