Step 1

Preheat oven to 425F (220C). Spray your largest baking dish (I used a deep 9 x 13-inch dish) with cooking spray.

Step 2

In the prepared dish (or in a separate bowl), whisk together the Alfredo sauce, beef broth, Worcestershire sauce, and sour cream until smooth and completely combined. Stir in the uncooked noodles, onion, meatballs, mushrooms, and garlic. Cover tightly with aluminum foil and bake for 30 minutes.

Step 3

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.

Step 4

In a small bowl, mix together breadcrumbs and melted butter. Sprinkle breadcrumbs over casserole and bake, uncovered, for 10 more minutes (or until topping is golden brown and pasta is tender).

Step 5

Garnish with fresh parsley, if desired.