01 -
Set your oven to 400°F (200°C) and give it some time to heat up while you prepare the casserole.
02 -
In a 9×13 inch casserole dish, add the uncooked elbow macaroni, milk, chicken broth, minced garlic, kosher salt, black pepper, Italian seasoning, and red pepper flakes (if using). Give everything a really good stir to ensure the macaroni is evenly distributed and not clumping together. This mixing step is crucial to prevent the pasta from sticking to the pan!
03 -
Cover the casserole dish tightly with aluminum foil. Bake for 20 minutes. The pasta will begin to cook and absorb some of the liquid during this time.
04 -
Remove the dish from the oven and carefully peel back the foil (watch out for hot steam!). Give the pasta a good stir - don't worry if there seems to be a lot of liquid at this point, it will thicken up nicely. Add the diced cooked chicken, broccoli florets, and about 2 cups of the grated white cheddar (reserve about ½ cup for topping). Stir until everything is well combined and the broccoli is moistened by the liquid. The residual heat will help melt the cheese and create a creamy sauce.
05 -
Sprinkle the remaining ½ cup of grated cheddar evenly over the top of the casserole. Return the dish to the oven, uncovered this time, and bake for an additional 20 minutes. The top should become golden and bubbly, and the broccoli should be tender but still have a bit of bite to it.
06 -
Remove from the oven and let the casserole rest for about 5 minutes. Serve in generous portions, topped with a sprinkle of grated parmesan cheese and an extra crack of fresh black pepper if desired. This dish is hearty enough to stand alone but also pairs well with a simple green salad on the side.