Tuna Casserole with Creamy Sauce

The smell of butter and onions melting together always pulls me into the kitchen, no matter what I was doing before. My grandmother made tuna casserole every Thursday without fail, and I used to hover around the stove watching her make the sauce, hoping she would let me taste a noodle before it went into the baking dish.

Last winter my neighbor came over with a bag of groceries and suggested we make dinner together. We ended up cooking this while her kids ran around the living room, and I learned that she adds an extra pinch of thyme right before baking something I do every time now.

Ingredients

• 250 g (9 oz) egg noodles or fusilli: Egg noodles hold onto the sauce beautifully, but fusilli works great too if that is what you have in the pantry
• 1 cup frozen peas: These little pops of sweetness balance the rich sauce and add such a nice texture throughout
• 1 small onion, finely chopped: Finely chopped means they practically disappear into the sauce while still adding that essential savory base
• 2 cloves garlic, minced: Fresh garlic makes such a difference here, do not be tempted to use the jarred stuff
• 2 cans (each 170 g/6 oz) tuna in water, drained: Water-packed tuna keeps the sauce from becoming too oily, and draining it well is crucial
• 2 tablespoons unsalted butter: This creates the roux base for your creamy sauce
• 2 tablespoons all-purpose flour: The flour thickens the sauce into that velvety texture we all love
• 1 1/2 cups (360 ml) milk: Whole milk gives the richest results, but 2% works perfectly fine
• 1/2 cup (120 ml) sour cream: This is the secret ingredient that makes the sauce taste like it came from a restaurant kitchen
• 1/2 teaspoon salt: Adjust this based on whether your butter is salted
• 1/4 teaspoon black pepper: Freshly ground pepper adds such a warm depth
• 1/2 teaspoon dried thyme (optional): Even if you think you do not like thyme, try it once because it transforms the whole dish
• 1/2 cup (60 g) shredded cheddar cheese: Sharp cheddar gives the best flavor punch
• 1 cup (60 g) panko breadcrumbs: Panko creates this incredibly light and crispy topping that regular breadcrumbs just cannot match
• 2 tablespoons unsalted butter, melted: Melting the butter helps the breadcrumbs turn that perfect golden brown
• 2 tablespoons grated Parmesan cheese: The Parmesan adds a salty, nutty richness to the crispy topping

Instructions

Get everything ready:

Preheat your oven to 190°C (375°F) and grease a 2-liter baking dish with butter

Cook the noodles:

Boil the pasta in salted water until al dente, then drain and set it aside while you make the sauce

Build the flavor base:

Melt 2 tablespoons butter in a large skillet over medium heat, then cook the onion and garlic for about 3 minutes until they are soft and smell amazing

Make the roux:

Sprinkle the flour into the skillet and stir constantly for 1 minute to cook out the raw flour taste

Create the creamy sauce:

Whisk in the milk gradually and let it simmer for 3 to 4 minutes until it thickens enough to coat the back of a spoon

Add the good stuff:

Remove the pan from heat and stir in the sour cream, salt, pepper, thyme if you are using it, and cheddar until everything is smooth and melted

Combine it all:

Gently fold in the tuna, peas, and cooked pasta until everything is evenly coated in that luscious sauce

Transfer to the dish:

Spoon the mixture into your prepared baking dish and spread it into an even layer

Make the crispy topping:

Mix the panko breadcrumbs, melted butter, and Parmesan in a small bowl until everything is well combined

Top it off:

Sprinkle the breadcrumb mixture evenly over the entire casserole

Bake until golden:

Bake for 20 to 25 minutes until you see the sauce bubbling up around the edges and the top is beautifully golden brown

Let it rest:

Cool for 5 minutes before serving so the sauce has time to set slightly

Save

This became my go-to dish when I moved into my first apartment and had barely any cooking skills. My roommates and I would gather around the small oven watching the top turn golden through the oven door, and it felt like we had created something magical together.

Make It Your Own

I have made so many versions of this over the years, and the beauty is how adaptable it is. Sometimes I add sautéed mushrooms when I want something earthier, or swap the cheddar for Swiss cheese when I am feeling fancy.

Perfect Pairings

A crisp green salad with a bright vinaigrette cuts through the richness perfectly, and I always keep a chilled white wine like Sauvignon Blanc on hand. The wine brightens up all those creamy flavors and makes the whole meal feel like a proper dinner party.

Serving Suggestions

This casserole is substantial enough to stand alone as a complete meal, which is exactly why it became such a weeknight hero in my house.

• Keep some extra Parmesan on the table for sprinkling
• Lemon wedges add a nice bright pop if you want to cut through the richness
• Crusty bread for soaking up any extra sauce is never a bad idea

Save

There is something so deeply comforting about a bubbling casserole coming out of the oven, and this one has never let me down. Enjoy every creamy, crunchy bite.

Recipe FAQs

→ Can I freeze tuna casserole before baking?

Yes, assemble the casserole completely including the topping, then wrap tightly and freeze for up to 3 months. Thaw overnight in the refrigerator before baking as directed.

→ What pasta works best for this dish?

Egg noodles are traditional and hold sauce beautifully, but fusilli, penne, or macaroni also work well. Choose shapes with nooks and crannies to capture the creamy sauce.

→ Can I use fresh tuna instead of canned?

You can use cooked fresh tuna, though canned provides the traditional flavor and texture. If using fresh, cook and flake it first, then reduce salt in the sauce since canned tuna contains sodium.

→ How do I know when the casserole is done?

The casserole is ready when the sauce bubbles around the edges and the breadcrumb topping turns golden brown, typically 20-25 minutes in a 190°C (375°F) oven.

→ Can I make this ahead of time?

Assemble the entire casserole up to 24 hours ahead, cover tightly, and refrigerate. You may need to add 5-10 minutes to the baking time since it will be cold.

→ What vegetables can I add?

Sautéed mushrooms, diced bell peppers, or steamed broccoli florets complement the flavors well. Add them during step 7 when folding in the tuna and peas.