Step 1: Cook the Pasta Shells
Bring a large pot of salted water to a boil. Cook the jumbo pasta shells according to the package instructions until al dente. Drain and rinse under cold water to stop the cooking process. Set aside on a clean towel to dry.

Step 2: Prepare the Filling
In a large mixing bowl, combine shredded chicken, chopped broccoli, ricotta cheese, mozzarella cheese, Parmesan cheese, egg, garlic powder, onion powder, salt, and pepper. Mix until well combined and set aside.

Step 3: Make the Alfredo Sauce
In a medium saucepan, melt butter over medium heat. Add minced garlic and sauté until fragrant, about 1 minute. Stir in heavy cream and bring to a gentle simmer. Gradually whisk in Parmesan cheese until the sauce is smooth and creamy. Season with Italian seasoning, salt, and pepper to taste. Remove from heat.

Step 4: Assemble the Stuffed Shells
Preheat your oven to 375°F (190°C). Spread 1 cup of Alfredo sauce evenly across the bottom of a 9×13-inch baking dish. Stuff each cooked pasta shell with the chicken and broccoli mixture and arrange them in the prepared dish. Pour the remaining Alfredo sauce over the stuffed shells, ensuring they’re well coated.

Step 5: Add the Toppings and Bake
Sprinkle the mozzarella cheese and Parmesan cheese over the stuffed shells. Cover the baking dish with foil and bake for 20 minutes. Remove the foil and bake for an additional 10–15 minutes, or until the cheese is melted and bubbly.

Step 6: Serve and Enjoy
Garnish with chopped parsley, if desired, and serve the stuffed shells hot with a side of garlic bread or a fresh green salad.