Step 1: Cook the Pasta Shells : Bring a large pot of salted water to a boil. Add jumbo shells and cook until al dente (about 9–10 minutes). Drain and rinse with cold water to prevent sticking. Lay them flat on a baking sheet to cool while you prepare the filling.

Step 2: Prepare the Chicken and Spinach Filling : In a large mixing bowl, combine shredded chicken, ricotta, mozzarella, Parmesan, spinach, egg, garlic powder, onion powder, salt, and black pepper. Mix until well combined and creamy. Taste and adjust seasoning if needed.

Step 3: Make the Alfredo Sauce :In a medium saucepan, melt butter over medium heat. Add minced garlic and sauté for 1 minute until fragrant (don’t brown it). Whisk in flour and cook for 30 seconds to remove the raw taste. Gradually whisk in heavy cream, stirring constantly until smooth. Add Parmesan cheese, Italian seasoning, salt, and pepper. Simmer on low heat for 2–3 minutes until thickened and silky.

Step 4: Assemble the Dish : Preheat oven to 375°F (190°C). Spread ½ cup of Alfredo sauce on the bottom of a greased 9x13-inch baking dish. Stuff each shell with about 2 tablespoons of the chicken-spinach mixture. Arrange the filled shells in the dish in a single layer. Pour the remaining Alfredo sauce evenly over the shells. Sprinkle mozzarella and Parmesan cheese on top.

Step 5: Bake : Cover the dish with foil and bake for 20 minutes. Remove foil and bake for another 10–15 minutes, until bubbly and slightly golden on top.

Step 6: Serve and Garnish :Let rest for 5 minutes before serving. Garnish with fresh parsley and extra Parmesan if desired.