Chicken Broccoli Tetrazzini Bake
Chicken And Broccoli Tetrazzini is a creamy, oven-baked pasta casserole that brings together tender chicken, broccoli, and plenty of melted cheese for a hearty dinner that feels comforting, reliable, and weeknight-friendly.
This is the kind of meal that works beautifully when you want something filling, familiar, and easy to bring to the table. It has that classic baked pasta appeal, but the broccoli keeps every bite from feeling too heavy.
The sauce is what makes it especially satisfying. A simple buttery base, chicken stock, milk, Parmesan, and mozzarella come together into a smooth, velvety coating that clings to the spaghetti and bakes up beautifully.
It is also a practical dinner for real life. You can use cooked chicken you already have on hand, prep the ingredients without much fuss, and serve it straight from the baking dish for a cozy family-style meal.
Chicken And Broccoli Tetrazzini Ingredients
Spaghetti brings structure to the casserole and gives you that classic tetrazzini-style bite. Breaking it in half makes the finished dish easier to scoop and serve.
Butter starts the sauce and gives it a rich, rounded base that helps the onion and garlic soften gently without browning too much.
Onion adds sweetness and depth. Finely dicing it helps the sauce stay smooth and evenly textured instead of chunky.
Garlic gives the casserole a savory backbone and makes the creamy cheese sauce taste fuller and more balanced.
Flour thickens the sauce so it coats the pasta well and holds everything together once baked.
Chicken stock and whole milk work together for a sauce that tastes rich without becoming overly heavy. The stock adds savoriness while the milk keeps the texture silky.
Parmesan cheese adds salty, nutty flavor and gives the sauce more depth than mozzarella alone.
Mozzarella cheese melts into the sauce and across the top, creating that gooey, bubbly finish that makes a baked casserole so appealing.
Italian seasoning adds a gentle herby note that ties the chicken, pasta, and cheese together.
Broccoli florets bring freshness, color, and a little texture, which helps balance the creamy pasta.
Cooked chicken makes this casserole hearty and keeps it convenient. Shredded or chopped chicken both work well, depending on the texture you like.
Cooking Steps
STEP 1: Heat your oven to 350°F and lightly prepare your baking dish. Cook the spaghetti until just tender, then drain it well and place it in a large bowl. Leave the pasta unrinsed so the sauce can cling better.
STEP 2: In a large pot, melt the butter over medium heat. Add the diced onion and minced garlic, then cook until the onion looks soft and translucent and the kitchen smells fragrant.
STEP 3: Sprinkle in the flour along with the salt and black pepper. Whisk continuously for about a minute so the flour cooks through and forms a smooth base for the sauce.
STEP 4: Slowly add the chicken stock and milk while whisking. Keep stirring until the mixture looks smooth and begins to thicken into a light cream sauce.
STEP 5: Stir in the Parmesan, Italian seasoning, and part of the mozzarella. Once the cheese melts, the sauce should look creamy, glossy, and well blended.
STEP 6: Pour the sauce over the cooked spaghetti, then add the chicken and broccoli. Toss until everything is evenly coated and the broccoli is distributed throughout the mixture.
STEP 7: Transfer everything to a 9×9-inch baking dish, top with the remaining mozzarella, cover, and bake until hot and bubbling. Uncover for the last part of baking so the cheese can melt fully and turn lightly golden before serving.
Can I use rotisserie chicken for this casserole?
Yes, rotisserie chicken fits this dish very well. It keeps prep simple and adds plenty of flavor, especially when you want a fast dinner. Just shred or chop it into bite-size pieces so it mixes evenly through the pasta.
Helpful Tips
- Cook the spaghetti just to al dente so it stays pleasantly firm after baking in the sauce.
- Cut the broccoli into small florets so it softens evenly and mixes well into each serving.
- Let the baked casserole rest for a few minutes before scooping so the sauce settles and the portions hold together better.
Do I need to cook the broccoli before baking?
Not necessarily. Small broccoli florets can soften nicely in the casserole as it bakes, especially when they are mixed into the warm sauce. If you prefer very tender broccoli, you can blanch it briefly first, but it is not required.
Perfect Pairings
A crisp green salad with a simple vinaigrette is a great contrast to the creamy pasta. The fresh, tangy flavor keeps the meal feeling balanced.
Garlic bread or warm breadsticks also work beautifully here. They are especially good for catching any extra cheese sauce left on the plate.
For something lighter on the side, roasted green beans or sautéed zucchini pair nicely without competing with the casserole’s rich texture.
Can I assemble it ahead of time?
Yes, this is a good make-ahead casserole. You can assemble it earlier in the day, cover it tightly, and refrigerate it until you are ready to bake. If it is going into the oven cold, it may need a few extra minutes so the center heats through properly.
Keeping Leftovers Fresh
Store leftovers in an airtight container in the refrigerator for up to 3 days. The sauce will continue to thicken as it sits, but the casserole reheats well.
To reheat a single portion, microwave it in short intervals until heated through. Adding a small splash of milk can help loosen the sauce and bring back some of its creamy texture.
For a larger amount, cover the baking dish and warm it in the oven until hot in the center. Keeping it covered for most of the reheating time helps prevent the top from drying out.
You can also freeze it if needed. Wrap it well and freeze for up to 2 months, then thaw in the refrigerator before reheating for the best texture.
How do I keep tetrazzini from drying out?
The key is a well-made sauce and not overbaking the casserole. Make sure the pasta is fully coated before it goes into the dish, keep it covered for the first part of baking, and reheat leftovers with a splash of milk if needed.
Chicken And Broccoli Tetrazzini
Ingredients
For the Pasta:
- 8 ounces spaghetti snapped in half
For the Sauce:
- 1 cup whole milk
- 1 tablespoon garlic minced
- 1/4 cup all-purpose flour
- 1/2 cup Parmesan cheese grated
- 1 teaspoon Italian seasoning
- 2 cups chicken stock
- 1/4 teaspoon freshly ground black pepper
- 1/4 cup unsalted butter
- 1 teaspoon sea salt
- 1 cup shredded mozzarella cheese
- 1/2 cup onion finely diced
For the Casserole:
- 1 pound broccoli cut into small florets
- 2 cups cooked chicken shredded or chopped
For the Topping:
- 1 cup mozzarella cheese shredded
Instructions
- Preheat the oven to 350°F.
- Cook the halved spaghetti in accordance with the package directions. Drain well once tender and place the pasta in a large mixing bowl. Do not rinse, as the natural starch helps the sauce cling to the noodles.
- Meanwhile, set a large stockpot over medium heat and melt the butter. Add the chopped onion and minced garlic, then sauté for about 4 minutes, or until the onion is soft and translucent.
- Sprinkle in the flour, sea salt, and black pepper. Whisk continuously for 30 to 60 seconds, allowing the mixture to bubble lightly so the flour loses its raw flavor.
- Gradually pour in the chicken stock and milk, whisking steadily until smooth. Continue cooking until the sauce begins to thicken slightly.
- Add the Parmesan, Italian seasoning, and 1 cup of mozzarella. Whisk until the cheeses are fully melted and the sauce becomes smooth and creamy.
- Pour the finished sauce over the drained spaghetti. Add the broccoli florets and cooked chicken, then stir until all components are evenly coated and well combined.
- Transfer the mixture to a 9×9-inch baking dish. Scatter the remaining 1 cup of shredded mozzarella evenly across the top.
- Cover the dish with a lid or aluminum foil and bake for 20 minutes. Remove the cover and continue baking for 10 minutes more, or until the casserole is bubbling and the cheese on top is lightly golden.
- Remove from the oven and let the casserole rest briefly before serving warm.