Tuna Casserole Without Canned Soup delivers creamy, comforting flavor with tender pasta, savory mushrooms, albacore tuna, sharp cheddar, and a crisp breadcrumb topping, all made with a smooth homemade sauce.
This from-scratch casserole is a dependable choice when you want a cozy family dinner without opening a can of condensed soup. The filling is rich and creamy, but it still tastes fresh because the sauce begins with sautéed onion, celery, garlic, and mushrooms.
Cooking the pasta just shy of al dente keeps it from becoming overly soft in the oven. Meanwhile, the combination of milk, broth, and a simple flour roux creates a sauce that coats every noodle without feeling heavy or gluey.
The finished casserole has everything you want in a comforting baked meal: flaky tuna, tender vegetables, bubbling cheddar, and golden buttered breadcrumbs. It is especially useful for weeknight dinners, casual gatherings, or meal prep because the components can be assembled ahead of time.
Ingredients for Tuna Casserole Without Canned Soup
Albacore tuna: Drain it thoroughly and separate it into flakes so it distributes evenly through the pasta without making the sauce watery.
Whole-wheat rotini or egg noodles: Rotini provides a slightly firmer, nuttier bite, while egg noodles create a softer and more traditional casserole texture.
Mushrooms: Cremini or button mushrooms add savory depth and make the homemade sauce taste fuller without relying on condensed soup.
Onion: A diced medium onion provides sweetness and a flavorful foundation for the filling.
Celery: Finely diced celery adds a gentle freshness and a small amount of texture to the creamy casserole.
Fresh garlic: Minced garlic strengthens the savory flavor of the mushrooms and sauce.
Unsalted butter: Butter is used to sauté the vegetables, enrich the sauce, prepare the baking dish, and moisten the breadcrumb topping.
All-purpose flour: Flour combines with the butter and vegetables to form the roux that thickens the sauce.
Milk: Room-temperature milk blends smoothly into the roux and gives the filling its creamy consistency.
Chicken stock or vegetable broth: Broth loosens the sauce while adding more flavor than milk alone.
Sharp cheddar cheese: Sharp cheddar remains noticeable after baking and forms a rich, melted layer across the top.
Breadcrumbs: Panko produces the crispiest finish, although standard dry breadcrumbs can also be used.
Kosher salt and black pepper: Because there is no salty condensed soup in the filling, proper seasoning is important for a balanced final dish.
Cooking Steps
STEP 1: Heat the oven to 375°F and generously butter the inside of a 9 × 13-inch baking dish. Prepare all the vegetables, drain and flake the tuna, shred the cheese, and measure the sauce ingredients before you begin cooking.
STEP 2: Bring a large pot of well-salted water to a boil. Cook the rotini or egg noodles until they are just under al dente, usually about 1 to 2 minutes less than the package directions suggest. Drain well and set the pasta aside while you prepare the filling.
STEP 3: Melt 2 tablespoons of butter in a large skillet over medium heat. Add the onion and celery, then cook for about 3 minutes until they begin to soften. Stir in the garlic and cook briefly, just until fragrant.
STEP 4: Add the chopped mushrooms to the skillet. Cook them for 8 to 10 minutes, stirring occasionally, until their moisture has evaporated and the edges begin to brown. Allowing the liquid to cook away prevents the casserole from becoming thin or watery.
STEP 5: Sprinkle the flour over the cooked vegetables and stir continuously for about 1 minute. Slowly pour in the room-temperature milk and broth, stirring as you add them so the flour incorporates without forming lumps. Simmer for 5 to 7 minutes, until the sauce coats the back of a spoon.
STEP 6: Season the sauce generously with kosher salt and freshly ground black pepper. Remove the skillet from the heat, then gently fold in the drained pasta and flaked tuna. Stir only until everything is evenly coated so the tuna retains some texture.
STEP 7: Spoon the mixture into the buttered baking dish and spread it into an even layer. Combine the breadcrumbs with 1 tablespoon of melted butter, then sprinkle them over the filling. Finish by distributing the shredded sharp cheddar across the surface.
STEP 8: Bake for approximately 20 minutes, until the sauce bubbles around the edges and the topping becomes golden. Let the casserole rest for 5 minutes before serving. This brief pause helps the sauce settle and cling to the pasta.
Serving Ideas for Tuna Casserole
A crisp green salad is one of the most useful pairings because its fresh texture balances the creamy pasta and melted cheese. Try mixed greens, cucumber, or romaine with a light vinaigrette rather than a heavy dressing.
Roasted green vegetables also work well. Broccoli, asparagus, or green beans provide color and a slightly caramelized flavor without competing with the casserole.
For a simple comfort-food dinner, serve the casserole with warm rolls or a crusty loaf. Bread is especially helpful for collecting any creamy mushroom sauce left on the plate.
Can I assemble the casserole ahead of time?
Yes. Prepare the pasta filling, transfer it to the buttered baking dish, and let it cool before covering and refrigerating it. Keep the buttered breadcrumbs separate so they remain crisp. Add the breadcrumbs and cheese immediately before baking.
How do I keep tuna casserole from becoming dry?
Avoid overcooking the pasta and make sure the sauce has thickened but is still pourable before adding the noodles. The pasta will absorb liquid while baking, so a sauce that looks slightly loose in the skillet usually produces the creamiest result.
Can I use egg noodles instead of rotini?
Egg noodles are an excellent choice and produce a softer, more classic casserole. Cook them only until slightly underdone because their delicate texture softens quickly in the oven. Drain them thoroughly before folding them into the sauce.
Why is my homemade sauce lumpy?
Lumps often form when cold liquid is poured into the roux too quickly. Use room-temperature milk, add the liquid gradually, and stir continuously. If a few small lumps remain, vigorous whisking usually smooths the sauce before the pasta is added.
Can I substitute a different cheese?
A flavorful melting cheese works best. White cheddar, Monterey Jack, or a mixture of cheddar and Parmesan can be used. Mild cheeses may become creamy but can taste less noticeable after baking, so season the sauce carefully when making a substitution.
Helpful Tips
- Cook the mushrooms until their released moisture has fully evaporated. This concentrates their flavor and prevents excess liquid from thinning the casserole.
- Taste the sauce before adding the pasta and tuna. It should be well seasoned because the noodles will soften and dilute the seasoning slightly.
- Add the breadcrumbs beneath or around the cheese rather than completely burying them. Exposed crumbs brown more effectively and create a crisper topping.
Keeping Leftovers Fresh
Allow leftover casserole to cool, then transfer it to an airtight container or cover the baking dish securely. Refrigerate it for up to 3 to 4 days.
For individual portions, reheat the casserole in the microwave until hot throughout. Covering the portion loosely helps retain moisture. If the filling appears thick, add a small splash of milk or broth before reheating.
For a crisper topping, warm larger portions in a 350°F oven. Cover the casserole loosely with foil for the first part of reheating, then remove the foil during the final few minutes. Heat until the center reaches a steaming-hot temperature.
The casserole can also be frozen for up to 2 months, although the pasta may soften slightly after thawing. Freeze it in tightly sealed portions for convenient meals. Thaw overnight in the refrigerator before reheating, and add fresh breadcrumbs if the original topping has lost its crunch.
Tuna Casserole Without Canned Soup
Ingredients
For the Pasta Filling
- 12 ounces albacore tuna packed in water thoroughly drained and separated into flakes
- 1 cup room-temperature milk
- 3 fresh garlic cloves finely minced
- 8 ounces whole-wheat rotini or egg noodles
- 16 ounces cremini or button mushrooms cut into bite-sized pieces
- ¼ cup all-purpose flour
- 1 cup chicken stock or vegetable broth
- 2 celery ribs cut into ¼-inch dice
- 2 tablespoons unsalted butter
- 1 medium onion cut into ½-inch dice, approximately 1 cup
- Kosher salt adjusted to taste
- Freshly ground black pepper adjusted to taste
For the Topping
- ½ cup breadcrumbs preferably panko for a crisper finish
- 1 cup shredded sharp cheddar cheese
- 1 tablespoon butter melted
For Preparing the Baking Dish
- Butter as required
Instructions
- Preheat the oven to 375°F. Coat the interior of a 9 × 13-inch baking dish generously with butter.
- Prepare the ingredients before cooking. Dice the onion and celery, finely mince the garlic, chop the mushrooms, drain and flake the tuna, and shred the cheddar cheese.
- Bring a large pot of generously salted water to a boil. Add the pasta and cook until just al dente, stopping approximately 1 to 2 minutes before the package’s recommended cooking time because the pasta will continue softening in the oven.
- Drain the pasta thoroughly and place it aside.
- Melt 2 tablespoons of butter in a large skillet over medium heat. Add the diced onion and celery, then cook for approximately 3 minutes, or until the vegetables begin to soften.
- Add the minced garlic and stir for about 30 seconds, cooking only until aromatic. Incorporate the chopped mushrooms and continue cooking for 8 to 10 minutes, stirring periodically, until their released liquid has evaporated and the mushrooms begin to brown.
- Distribute the flour evenly over the sautéed vegetables. Stir continuously for approximately 1 minute to remove the raw flour flavor and form the foundation of the sauce.
- Gradually add the room-temperature milk and the chicken or vegetable stock, stirring constantly to maintain a smooth consistency.
- Cook the sauce over medium heat for 5 to 7 minutes, stirring frequently, until it becomes thick enough to cling to the back of a spoon. Season to taste with kosher salt and freshly ground black pepper.
- Combine the melted tablespoon of butter with the breadcrumbs in a small bowl. Stir until the crumbs are evenly moistened, then reserve the mixture for the topping.
- Remove the skillet from the heat. Gently fold the cooked pasta and drained tuna into the mushroom sauce until the ingredients are evenly distributed and fully coated.
- Transfer the tuna and pasta mixture to the prepared baking dish, spreading it into an even layer.
- Scatter the buttered breadcrumbs uniformly over the casserole, then distribute the shredded sharp cheddar cheese across the surface.
- Bake for 20 minutes, or until the edges are bubbling and the topping has developed a golden-brown finish.
- Allow the casserole to stand for 5 minutes before serving so the filling can settle slightly while remaining hot and creamy.