This oven baked 4-ingredient chicken tetrazzini is the closest I’ve come to my grandmother’s legendary Sunday-after-church casserole. Every week we’d walk into her house and you could smell the creamy pasta and roasted chicken before you even took off your shoes. She never used fancy ingredients or exact measurements, just simple things she always had on hand and a well-loved oval casserole dish. I streamlined her method into four practical ingredients and an easy, busy-weeknight-friendly process, but the result still has that old-school, church-basement-potluck comfort: tender chicken, twirly pasta, a rich, creamy sauce, and a bubbly, golden cheese top.
Serve this chicken tetrazzini straight from the hot casserole dish with a big spoon so everyone can scoop out those cheesy, creamy strands of pasta. It pairs really well with a simple green salad tossed in a tangy vinaigrette to cut through the richness, or just some steamed green beans or broccoli. Garlic bread or buttered dinner rolls are perfect for catching any extra sauce in the bottom of the dish. For a cozy Sunday vibe like my grandma’s, add a bowl of grapes or sliced oranges on the table and finish with something simple for dessert, like brownies or store-bought cookies.
Oven Baked 4-Ingredient Chicken TetrazziniServings: 6
Ingredients
12 oz dry spaghetti (or linguine)
3 cups cooked chicken, shredded or chopped
3 cups shredded mozzarella cheese, divided
2 cans (10.5 oz each) condensed cream of mushroom soup
1 1/2 cups water
1/2 teaspoon salt, or to taste
1/2 teaspoon black pepper, or to taste
Nonstick cooking spray or a little butter for greasing the dish
Directions
Preheat your oven to 350°F (175°C). Lightly grease an oval ceramic casserole dish (about 9x13-inch equivalent) with nonstick spray or a little butter. This helps keep the pasta from sticking and makes cleanup easier.
Bring a large pot of salted water to a boil. Break the spaghetti in half so it fits easily in the pot and later in the casserole dish, just like my grandma did. Cook the pasta for 2 minutes LESS than the package directions for al dente. You want it slightly underdone because it will continue to cook in the oven.
While the pasta cooks, in a large bowl whisk together the condensed cream of mushroom soup and the water until smooth. Season with the salt and black pepper. This simple mix becomes the creamy sauce that soaks into every strand of pasta.
Drain the spaghetti well, shaking off extra water so you don’t water down the sauce. Immediately add the hot pasta to the bowl with the soup mixture and toss until every strand is coated.
Stir the cooked chicken into the creamy pasta mixture until it’s evenly distributed. You want chunks of chicken in every scoop, so take a second to mix it well.
Add 2 cups of the shredded mozzarella cheese to the bowl and gently fold it through the pasta and chicken. It will start to get a little stretchy and messy—that’s what you want. This step helps create that ultra-creamy, cheesy center my grandma’s casserole was known for.
Transfer the mixture to the prepared oval casserole dish, spreading it out into an even layer. Press it down lightly with the back of a spoon so there aren’t big air pockets.
Sprinkle the remaining 1 cup of shredded mozzarella evenly over the top. Try to cover as much of the surface as you can so you get that golden, bubbly cheese layer.
Cover the casserole tightly with foil and bake in the preheated oven for 25 minutes. Covering helps the pasta finish cooking in the sauce without drying out.
After 25 minutes, carefully remove the foil (watch for steam) and return the dish to the oven. Bake uncovered for another 15–20 minutes, or until the top is melted, lightly golden in spots, and the edges are bubbling. If you like a deeper golden top, you can broil it for 1–2 extra minutes, watching closely so it doesn’t burn.
Let the tetrazzini rest on the counter for 10 minutes before serving. This helps the sauce thicken slightly so you can scoop out big, generous portions without it sliding all over the place. Serve straight from the dish with a large spoon, making sure to get some of the stretchy top cheese with every serving.
Variations & Tips
To stay true to the 4-ingredient spirit, the base is just pasta, cooked chicken, cheese, and condensed soup, but you can tweak it to fit your life and what’s in your fridge. Use rotisserie chicken for a fast weeknight shortcut, or leftover roasted turkey after the holidays. Swap the mozzarella for a blend of mozzarella and Parmesan or even Monterey Jack for a slightly different flavor. If you don’t love cream of mushroom, cream of chicken or cream of celery soup also works well. For extra veggies, stir in thawed frozen peas, chopped cooked broccoli, or a handful of baby spinach before baking (just know that technically adds ingredients beyond the core four). To prep ahead, assemble the casserole up to a day in advance, cover tightly, and refrigerate; when baking from cold, add 10–15 minutes to the covered bake time and make sure it’s hot and bubbling in the center. For food safety, always start with fully cooked chicken—if you’re cooking it yourself, cook to an internal temperature of 165°F (74°C) and cool it slightly before mixing into the casserole. Don’t leave the baked tetrazzini at room temperature for more than 2 hours; refrigerate leftovers in a shallow container and eat within 3–4 days, reheating until hot and steaming all the way through. If freezing, cool completely, wrap well, and freeze up to 2 months; thaw overnight in the fridge before reheating, adding a splash of water or milk if it seems dry.
