Classic Tuna Melt Casserole – Sometimes, all you need is a dish that wraps you in warmth and makes you feel at home. This Classic Tuna Melt Casserole does exactly that. Picture tender rigatoni, rich tuna, and gooey Swiss and cheddar cheeses, topped with sweet, juicy tomato slices. It’s simple, nostalgic, and has that melt-in-your-mouth comfort that we all crave when life gets busy.
The first time I put this casserole together, I wasn’t sure if it would be a hit or miss. A baked dish with tuna? It felt like a gamble. But as it cooked, the kitchen filled with the cozy, familiar scent of cheese and caramelized onions. My husband wandered in, drawn by the smell, and my child—usually suspicious of anything involving tuna—gave an excited, wide-eyed look at the bubbling, golden dish. We took our first bites, and I knew this wasn’t just dinner; it was comfort on a plate. The kind that makes everyone lean back and sigh happily, forks scraping the plate for that last cheesy bite. It surprised me how something so simple could feel so special.
What makes this Classic Tuna Melt Casserole truly special?
This isn’t just any casserole—it’s your go-to for those nights when you need warmth and flavor without the fuss. It’s like your favorite tuna melt sandwich, but heartier, creamier, and baked to perfection. The Swiss and cheddar create a perfectly melty, rich sauce that hugs every piece of pasta, and the tomatoes on top add just the right pop of freshness. Quick, satisfying, and crowd-pleasing, this dish brings everyone to the table with a smile.
What You Need To Make This Classic Tuna Melt Casserole Recipe?
Rigatoni: This pasta is perfect for casseroles because those big tubes hold onto the sauce so well. If you don’t have rigatoni on hand, don’t sweat it—penne or ziti will do just fine.
Sweet Onion: Slicing it thin and cooking it until it’s nice and soft adds a lovely touch of sweetness. It blends right into the dish, giving it that subtle depth without overpowering the flavors.
Butter: We’re using butter to start the sauce, which gives it a rich base. No skimping here; it’s the start of all that creamy goodness.
Swiss and Cheddar Cheeses: This combo is what makes the magic happen. Swiss adds that slightly nutty, melty goodness, while cheddar brings a bit of sharpness. The blend keeps each bite interesting.
Tuna: Good old canned tuna in water works best here. Drain it well and give it a gentle flake with a fork. It mixes in smoothly and doesn’t overpower the dish.
Tomatoes: Fresh tomato slices on top give the casserole a pop of color and a burst of juiciness. Go for ripe but firm ones, so they hold up during baking.
Whole Milk: Using whole milk makes the sauce creamy without being too heavy. If you need to substitute, half-and-half could work for extra richness.
Steps To Make Classic Tuna Melt Casserole:
Start by preheating your oven to 400°F. Grease a 9×13-inch baking dish with butter or nonstick spray and set it aside for later.
Cook the rigatoni in a large pot of salted boiling water, but keep it just shy of fully cooked—about 2 minutes before the package says it’s done. Drain it and put it back in the pot for now.
Melt the butter in a medium saucepan over medium heat. Add the sliced onion and let it cook for around 5 minutes until it softens and fills your kitchen with that sweet, savory aroma.
Sprinkle the flour over the onions and stir continuously for about a minute. Gradually pour in the milk, turning the heat up to medium-high. Keep stirring as the sauce bubbles and thickens. Add a pinch of salt and a dash of black pepper to bring out the flavors.
Want To Save This Recipe?
Take the saucepan off the heat and stir in half a cup each of the Swiss and cheddar cheeses until they melt and blend into a smooth, creamy sauce.
Pour the cheesy sauce over the rigatoni in the pot, add the flaked tuna, and stir it all together until the pasta is well coated.
Spoon the pasta mixture into your greased baking dish. Arrange the tomato slices on top and sprinkle the remaining cheese evenly across the surface.
Cover the dish with foil and slide it into the oven. Bake for 20 minutes until it’s hot and bubbling.
Remove the foil and bake for another 10 minutes or so, letting the cheese on top melt and turn a beautiful golden color.
Let the casserole rest for a few minutes before serving—this helps it set up and makes slicing and serving a breeze. Dig in and enjoy!
Tip:
Want to add an extra layer of texture and flavor? Mix some panko breadcrumbs with a little melted butter and sprinkle it over the top before baking. When it comes out of the oven, you’ll have this irresistible golden, crispy crust that perfectly contrasts with the creamy, cheesy pasta underneath. Trust me, that bit of crunch makes every bite a little more special and keeps everyone coming back for seconds. And here’s another idea—if you’re a fan of heat, add a sprinkle of red pepper flakes or a dash of hot sauce into the cheese sauce for a subtle kick. Little tweaks like these can really make this casserole your own.
Frequently Asked Questions:
Can I make this casserole ahead of time?
Yes, definitely! You can prep the entire casserole, cover it, and store it in the fridge for up to a day. When you’re ready to bake, just add an extra 5-10 minutes to the cooking time to make sure it’s heated through.
Can I switch out the cheeses for something else?
Of course! If Swiss or cheddar isn’t your thing, feel free to use what you like—Gruyere, mozzarella, or even a mix of Monterey Jack and sharp provolone can be delicious. Just make sure it’s a cheese that melts well.
What can I serve with this casserole?
A light, crisp side salad or some steamed green veggies pair perfectly with this rich dish. A slice of crusty bread is also great for mopping up any leftover cheesy goodness.
<Remember it later>
Planning to try this recipe soon? Pin it for a quick find later!
<Remember it later>
Planning to try this recipe soon? Pin it for a quick find later!
Classic Tuna Melt Casserole
Ingredients
- 16 ounces large rigatoni
- 1 sweet onion halved and thinly sliced
- 3 tbsp butter
- 2 tbsp flour
- 4 c whole milk
- 1 c grated Swiss cheese
- 1 c grated cheddar cheese
- 4 ounces chunk tuna in water drained and flaked
- 3 medium to large tomatoes sliced 1/4 inch thick
- Kosher salt and freshly ground black pepper to taste
Instructions
- First, set your oven to 400°F and grease a 9x13-inch baking dish with a bit of butter or nonstick spray. Set it aside for later.
- Get a big pot of water on the stove, add a good pinch of salt, and bring it to a boil. Cook the rigatoni, but stop about 2 minutes before it’s fully done according to the package. Drain the pasta and toss it back into the pot.
- Melt the butter in a medium saucepan over medium heat. Add the sliced onions and cook them for about 5 minutes until they become soft and fragrant.
- Sprinkle the flour over the onions and stir constantly for about a minute. Slowly pour in the milk while stirring, and turn the heat up to medium-high. Keep stirring until you see the sauce bubbling and starting to thicken up. Add a pinch of salt and some black pepper to taste.
- Take the saucepan off the heat and stir in 1/2 cup of the Swiss cheese and 1/2 cup of the cheddar until it melts smoothly into the sauce.
- Pour the cheesy sauce over the rigatoni in the pot. Add the flaked tuna and mix gently until everything is combined.
- Scoop the pasta mixture into your greased baking dish, spreading it out evenly. Lay the tomato slices over the top and sprinkle the remaining cheese evenly.
- Cover the dish with foil and bake for about 20 minutes, or until it’s hot and bubbly.
- Remove the foil and bake for another 10 minutes, letting the cheese get melted and golden.
- Give the casserole a few minutes to rest before digging in. This helps it set so it’s easier to slice and serve. Enjoy every comforting bite!
Notes
I’m Bitty, owner of nodashofgluten.com, where I share simple, delicious recipes for all tastes, including gluten-free. Check out my “About Me” page for more info!
