Preheat oven to 425 degrees F (220C). Spray an 8-inch square baking dish with cooking spray.
In the prepared dish (or in a separate bowl), stir together cooked chicken, artichoke hearts, asparagus, carrots, uncooked pasta, chicken broth, about half of the chives, half of the parsley, minced garlic, and salt, and 2 tablespoons of Parmesan.
Cover the dish tightly with foil and bake for 35 minutes.
Uncover; stir. 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.
Stir in the frozen peas and sprinkle remaining 2 tablespoons Parmesan over the top. Bake uncovered for 5-10 more minutes (or until pasta is tender).
Garnish with remaining chives and parsley just before serving.