Preheat the oven to 375°F (190°C).
Cook noodles according to package instructions; drain and set aside.
In a skillet, melt butter over medium heat and sauté onion and garlic until translucent.
Add the meatballs to the skillet and heat through.
Stir in the mushroom soup, sour cream, and beef broth until well combined.
Combine the meatball mixture with the cooked noodles and transfer to a baking dish.
Sprinkle with mozzarella and Parmesan cheeses.
Bake for 25-30 minutes until bubbly and golden on top.
Garnish with fresh parsley before serving.
