This creamy tuna pasta bake is the kind of dinner I make when I want something comforting, straightforward, and reliable. It comes together from pantry staples and a few simple steps, and it rewards you with a golden, bubbling top and a rich, velvety sauce inside. No fuss, just good food that feeds a small crowd or makes excellent leftovers.

I like this recipe because it balances creamy sauce, tender pasta, and flaky tuna without leaning on complicated techniques. The sauce is a classic roux-based white sauce: butter, flour, milk, seasoning, and melted mozzarella. Fold in peas, sweet corn, and tuna, top with more mozzarella, and a quick bake-and-broil finishes it with a crisp, cheesy top.

Below you’ll find the ingredients (clean and clear), the step-by-step directions exactly as written, and practical notes for troubleshooting, variations, and storage. Read through once, then cook with confidence.

Gather These Ingredients

3 tablespoons unsalted butter (50 grams) — melts to form the base of the roux; use unsalted to control the salt level.
¼ cup (50 grams) all-purpose flour — thickens the sauce into a creamy béchamel when cooked with butter.
2.5 cups (600 ml) whole milk — provides richness; whole milk gives the creamiest result.
¼ teaspoon ground nutmeg — a small touch brightens the béchamel; a little goes a long way.
1 teaspoon Italian seasoning — adds herbal depth; use a blend you like.
¼ teaspoon ground black pepper — for warm spice; adjust to taste.
1 teaspoon salt — seasons the sauce; add more later only if needed.
1 clove garlic crushed — a quick hit of garlic while you start the sauce.
1 cup (100 grams) mozzarella cheese grated – divided — half goes into the sauce for creaminess, half is reserved for a melty, golden top.
200 grams peas — sweet, tender pops of green; use thawed if frozen.
200 grams sweet corn — adds sweetness and texture; drain if canned.
300 grams canned tuna drained and flaked — the main protein; drain well and flake to distribute evenly.
4 cups (400 grams) dried pasta — cooks al dente before baking so it doesn’t overcook in the oven.
2 tablespoons Parsley chopped – for serving — fresh parsley brightens the finished dish; sprinkle just before serving.

Creamy Tuna Pasta Bake (Tuna Casserole) — Do This Next

Preheat the oven to 180°C (356°F). Prepare a 20 x 30 cm (9 x 12 inch) baking dish and set it nearby.
Cook the 4 cups (400 g) dried pasta according to the package instructions until al dente. Drain and set aside.
In a large saucepan over medium heat, melt 3 tablespoons (50 g) unsalted butter. Add the 1 crushed garlic clove and cook, stirring, about 30 seconds until fragrant.
Add 1/4 cup (50 g) all-purpose flour to the pan and stir constantly with a spatula to form a paste (roux). Cook, stirring, about 1 minute to remove the raw flour taste.
Gradually pour in 2.5 cups (600 ml) whole milk in a thin stream, whisking continuously to prevent lumps. Continue to cook and whisk until the sauce is smooth and has thickened to a creamy consistency (a few minutes).
Whisk in 1 teaspoon Italian seasoning, 1/4 teaspoon ground nutmeg, 1/4 teaspoon ground black pepper, and 1 teaspoon salt until evenly combined.
Stir in half of the grated mozzarella (1/2 cup / 50 g) and mix until the cheese has melted into the sauce.
Add the cooked pasta, 200 g peas, 200 g sweet corn, and 300 g drained, flaked canned tuna to the sauce. Gently fold everything together until evenly combined.
Pour the mixture into the prepared baking dish and spread into an even layer. Sprinkle the remaining grated mozzarella (1/2 cup / 50 g) evenly over the top.
Bake uncovered at 180°C (356°F) for 15 minutes. Then switch the oven to broil/grill and broil for 3–5 minutes, watching closely, until the top is golden and beginning to brown.
Remove from the oven, garnish with 2 tablespoons chopped parsley, let rest briefly, and serve warm.

What Makes This Recipe Special

This casserole hits comforting notes without complicated steps. The difference-maker is the simple béchamel-style sauce — a butter-and-flour roux whisked with whole milk — which gives the dish a velvety mouthfeel that canned soups or premade sauces can’t match. Melting mozzarella in the sauce and again on top creates both creaminess inside and an attractive, cheesy crust on top.

Another strength is balance: pasta for body, tuna for protein, peas and corn for color and texture. It’s forgiving, too — it tolerates small timing variations and is easy to scale within reason.

Low-Carb/Keto Alternatives

If you want to reduce carbs without changing the recipe’s spirit, focus on proportions rather than inventing new components. Reduce the amount of pasta and increase the tuna and any vegetables you prefer from the recipe list. That keeps the same flavors while lowering the total carbohydrate content. Also, go lighter on the sweet corn (it’s one of the higher-carb items here).

Other straightforward approaches: serve smaller portions with a large green side salad, or use a smaller amount of pasta mixed more heavily with the sauce and tuna so the dish feels hearty but uses fewer grains.

Before You Start: Equipment

Gather these tools so the cook goes smoothly:

Oven — preheat to 180°C (356°F) before baking.
20 x 30 cm (9 x 12 inch) baking dish — the recipe’s timing and depth assume this size.
Large saucepan — for melting butter, making the roux, and finishing the sauce.
Whisk — essential to prevent lumps when adding milk.
Spatula — for stirring the roux and folding the pasta mixture.
Colander — to drain the cooked pasta and the canned tuna.

Learn from These Mistakes

Common issues are easy to fix once you know the cause:

Gummy pasta: Overcooking the pasta before baking will make it mushy. Cook to al dente and drain promptly.
Lumpy sauce: Adding milk too quickly to the roux causes lumps. Pour milk in a thin stream while whisking continuously.
Sauce too thin: If the sauce hasn’t thickened, cook it a bit longer over medium heat while whisking. The roux needs time to activate.
Soggy casserole: Using a baking dish that’s too large will spread the mixture thin. Use the recommended 20 x 30 cm (9 x 12 inch) dish for the intended depth.
Burnt top: Broil only until the mozzarella is golden and bubbling — watch closely for the final 1–2 minutes.

Make It Your Way

Small tweaks can tailor the bake to your household without changing the method:

Cheesier: Fold a little more of the grated mozzarella into the sauce if you prefer extra stringiness.
More protein: Add an extra can of tuna (drained) to boost protein and reduce the relative pasta amount.
Veg-forward: Increase the peas and reduce the pasta slightly for more color and a lighter feel while keeping the same technique.
Herb twist: Stir some parsley into the sauce rather than only sprinkling it on top for a brighter, more integrated finish.

What Could Go Wrong

Here are likely problems and how to prevent or fix them:

Spoiled flavor from under-seasoning: Taste the sauce before combining with pasta; adjust salt and pepper carefully. Remember the tuna may contribute salt too.
Watery leftovers: If the bake is very moist after cooling, reheat covered, then uncover briefly to allow excess moisture to evaporate. A short stint under the broiler will help re-crisp the top.
Unpleasant texture from cold dairy: When adding mozzarella to the hot sauce, ensure the sauce is hot but not boiling — this helps the cheese melt smoothly.
Inconsistent heating: If your oven runs hot or cool, use an oven thermometer and adjust times slightly. The broiler step requires close attention regardless.

Shelf Life & Storage

Store cooled leftovers in an airtight container in the refrigerator for up to 3 days. Reheat gently in the oven (covered at 160–170°C until warmed through) or microwave in portions. For the oven, uncover for the last few minutes to refresh the top.

You can freeze portions for up to 2 months. Thaw in the refrigerator overnight before reheating, and reheat in the oven from chilled rather than frozen when possible to preserve texture. Note that the texture of peas and corn can change slightly after freezing and reheating.

Your Questions, Answered

Q: Can I use frozen peas and corn?
A: Yes. Thaw and drain them before adding so they don’t add excess water to the sauce.

Q: Do I need to drain the canned tuna?
A: Definitely drain and flake the tuna well so it distributes evenly and doesn’t create wet pockets.

Q: Can I make this ahead?
A: Assemble the casserole up to the baking step, cover, and refrigerate for a few hours before baking. If chilled, you may need to add a few extra minutes to the bake so it heats through. For longer make-ahead plans, assemble and freeze; bake from thawed for best results.

Q: What pasta shape works best?
A: Use a short pasta that holds sauce — penne, fusilli, shells, or similar. The recipe’s specified volume and bake time assume a short shape and 4 cups (400 g) dried pasta total.

That’s a Wrap

This Creamy Tuna Pasta Bake (Tuna Casserole) is dependable weeknight comfort: unfussy, crowd-pleasing, and forgiving. Read the steps once, prep your equipment and ingredients, then follow the simple sequence — roux, milk, cheese, mix, bake, broil. The results are creamy, cheesy, and built for sharing or saving for later meals.

Make it your way by shifting the pasta-to-protein ratio, adding more cheese, or brightening it with extra parsley. Keep an eye on the broiler and drain your tuna well, and you’ll have a warm, satisfying dinner in less time than you might think.

Print Recipe Pin Recipe

Creamy Tuna Pasta Bake (Tuna Casserole)

A creamy, cheesy tuna pasta bake with peas and sweet corn, topped with melted mozzarella and baked until golden.

Servings: 6 servings

Ingredients

?3 tablespoonsunsalted butter 50 grams
?1/4 cup 50 gramsall-purpose flour
?2.5 cups 600 mlwhole milk
?1/4 teaspoonground nutmeg
?1 teaspoonItalian seasoning
?1/4 teaspoonground black pepper
?1 teaspoonsalt
?1 clovegarliccrushed
?1 cup 100 gramsmozzarella cheesegrated – divided
?200 gramspeas
?200 gramssweet corn
?300 gramscanned tunadrained and flaked
?4 cups 400 gramsdried pasta
?2 tablespoonsParsleychopped – for serving

Instructions

Preheat the oven to 180°C (356°F). Prepare a 20 x 30 cm (9 x 12 inch) baking dish and set it nearby.
Cook the 4 cups (400 g) dried pasta according to the package instructions until al dente. Drain and set aside.
In a large saucepan over medium heat, melt 3 tablespoons (50 g) unsalted butter. Add the 1 crushed garlic clove and cook, stirring, about 30 seconds until fragrant.
Add 1/4 cup (50 g) all-purpose flour to the pan and stir constantly with a spatula to form a paste (roux). Cook, stirring, about 1 minute to remove the raw flour taste.
Gradually pour in 2.5 cups (600 ml) whole milk in a thin stream, whisking continuously to prevent lumps. Continue to cook and whisk until the sauce is smooth and has thickened to a creamy consistency (a few minutes).
Whisk in 1 teaspoon Italian seasoning, 1/4 teaspoon ground nutmeg, 1/4 teaspoon ground black pepper, and 1 teaspoon salt until evenly combined.
Stir in half of the grated mozzarella (1/2 cup / 50 g) and mix until the cheese has melted into the sauce.
Add the cooked pasta, 200 g peas, 200 g sweet corn, and 300 g drained, flaked canned tuna to the sauce. Gently fold everything together until evenly combined.
Pour the mixture into the prepared baking dish and spread into an even layer. Sprinkle the remaining grated mozzarella (1/2 cup / 50 g) evenly over the top.
Bake uncovered at 180°C (356°F) for 15 minutes. Then switch the oven to broil/grill and broil for 3–5 minutes, watching closely, until the top is golden and beginning to brown.
Remove from the oven, garnish with 2 tablespoons chopped parsley, let rest briefly, and serve warm.

Equipment

20x30cm – 9×12 inches baking dish

Prep Time20

Cook Time10

Total Time30