Preheat your oven to 375°F (190°C) and lightly grease a 9x13-inch (or similar size) baking dish. Begin by bringing a large pot of salted water to a boil. Add the whole wheat penne and cook it until it's slightly underdone—about 2 minutes less than the package instructions recommend. This is important because the pasta will finish cooking in the oven. To check, bite into a piece and look for a tiny white dot in the center—that means it's ready. Drain the pasta and rinse it with cold water to stop the cooking process.
While the pasta is cooking, steam the broccoli florets just until they turn a vibrant green and are slightly tender but still firm. Rinse them with cold water immediately to preserve the color and stop further cooking.
In a large mixing bowl, combine the cream of chicken soup and the skim milk. Stir until the mixture is smooth.
Spread 3 tablespoons of the creamy mixture over the bottom of your prepared baking dish.
Add the cooked pasta evenly over the base. On top of the pasta, layer the cubed roasted chicken breast.
Then, add the steamed broccoli florets, spreading them evenly. Sprinkle the crumbled bacon over the broccoli, making sure it’s distributed throughout.
Pour the remaining cream of chicken and milk mixture evenly over the top, letting it soak into the layers. Finally, sprinkle the shredded cheddar cheese over everything.
Cover the dish with foil and bake for 20 minutes. Remove the foil and bake for 10 more minutes, until the cheese is melted, bubbly, and lightly golden. Let it rest for 5 minutes before serving so the layers can settle.