Preheat your oven to 180°C (350°F). Lightly coat a 33×23 cm (9×13 inch) baking dish with non-stick spray or a thin layer of oil.
Bring a large pot of salted water to a boil. Cook the jumbo pasta shells according to package directions until just al dente — tender but still slightly firm. Avoid overcooking, as they’ll continue baking later.
Drain and rinse the shells under cold water to stop the cooking process. Spread them out on a clean tray or lightly oiled surface to cool while you prepare the filling.
Step 2: Prepare the Filling
Reserve 120 ml (½ cup) of the Alfredo sauce for topping later. In a large mixing bowl, combine the remaining Alfredo sauce with diced chicken, thawed broccoli, 75 g of cheddar cheese, and the Parmesan cheese.
Stir until all ingredients are evenly coated and the mixture is creamy. The Alfredo sauce acts as a binder, while the cheeses enrich the filling and the broccoli adds texture and freshness.
Step 3: Assemble the Shells
Using a spoon, carefully fill each cooled pasta shell with the chicken-broccoli mixture. You should have enough filling for about 24 shells, depending on size and fullness.
Arrange the stuffed shells in a single layer inside the prepared baking dish, fitting them snugly but not overcrowded. This ensures even baking and proper heat circulation.
Step 4: Add the Finishing Touches
Drizzle the reserved Alfredo sauce evenly over the filled shells, letting it seep between them for extra creaminess.
Sprinkle the remaining 25 g of cheddar cheese across the top. The extra cheese will melt into a beautiful, golden layer during baking.
Step 5: Bake and Serve
Place the dish in the preheated oven and bake for 20 minutes, or until the sauce is bubbling and the cheese on top is fully melted and slightly golden.
Remove from the oven and allow to cool for 5 minutes before serving — this resting time helps the filling set slightly, making the shells easier to plate.
