1. Prepare the Filling

• In a large mixing bowl, combine the shredded chicken, cooked broccoli, cheddar or mozzarella cheese, and Parmesan cheese.
• Pour ½ cup of the Alfredo sauce into the mixture and stir until well blended. Season with salt and pepper to taste.

2. Stuff the Shells

• Using a spoon or piping bag, carefully stuff each cooked jumbo shell with the prepared filling. Be generous but avoid overfilling to prevent spillage during baking.

3. Prepare the Baking Dish

• Preheat your oven to 375°F (190°C).
• Spread 1 cup of Alfredo sauce evenly over the bottom of a greased 9×13-inch baking dish. If using spaghetti sauce for an extra layer of flavor, spread it on the bottom first before adding the Alfredo sauce.

4. Arrange and Top

• Place the stuffed shells in a single layer in the baking dish.
• Pour the remaining Alfredo sauce over the shells, ensuring they are well-covered.
• Sprinkle additional mozzarella or Parmesan cheese on top for a golden, cheesy crust.

5. Bake

• Cover the dish with aluminum foil and bake for 25 minutes.
• Remove the foil and bake for an additional 10 minutes, or until the cheese is bubbly and slightly golden.

6. Serve

• Allow the dish to rest for 5 minutes before serving. Garnish with chopped parsley or basil for added flavor and presentation.