This Creamy Baked Tuna Mornay with Golden Cheese Crust is the ultimate comfort food casserole. Tender flakes of tuna are folded into a rich, velvety cheese sauce with sweet pops of peas and corn, then baked until bubbling and golden on top. It’s hearty, satisfying, and perfect for family dinners or meal prep.

Why You’ll Love This Recipe

This dish is pure comfort in every bite. The creamy homemade sauce is smooth and flavorful, balanced with a hint of Dijon mustard and fresh lemon juice to brighten the richness. The golden cheese crust adds a deliciously bubbly finish that makes it irresistible straight from the oven.

You’ll also love how simple it is to prepare. Using pantry staples like canned tuna and frozen vegetables makes this recipe both convenient and budget-friendly. It’s a reliable go-to meal that feels special without requiring complicated techniques.

It’s family-friendly, filling, and perfect for feeding a crowd. Plus, it reheats beautifully, making it ideal for leftovers.

Ingredients

(Tip: You’ll find the full list of ingredients and measurements in the recipe card below.)

2 x 425 g cans tuna in springwater, drained well
2 tablespoons unsalted butter
2 tablespoons plain flour
2 cups full cream milk
1/2 cup thickened cream
1 cup grated tasty cheese, plus extra for topping
1 cup frozen peas and corn
1/2 cup onion, finely chopped
1 teaspoon Dijon mustard
1 teaspoon lemon juice
1/2 teaspoon salt
1/4 teaspoon freshly ground black pepper

Directions

Preheat your oven to 180°C (fan forced). Lightly grease a medium-sized baking dish to prevent sticking.

In a large saucepan over medium heat, melt the butter. Once melted, add the finely chopped onion and cook for 2–3 minutes until soft and translucent, stirring occasionally.

Add the plain flour to the saucepan and stir continuously for 1 minute to form a smooth roux. This step removes the raw flour taste and helps thicken the sauce.

Gradually pour in the milk and thickened cream while whisking constantly to prevent lumps. Continue stirring over medium heat until the sauce thickens and coats the back of a spoon.

Reduce the heat to low and stir in the grated tasty cheese, Dijon mustard, lemon juice, salt, and freshly ground black pepper. Mix until the cheese is completely melted and the sauce is smooth and creamy.

Gently fold in the drained tuna along with the frozen peas and corn. Stir carefully to combine without breaking up the tuna too much.

Transfer the mixture into the prepared baking dish and smooth the top evenly with a spatula.

Sprinkle extra grated cheese evenly over the surface.

Bake for 20–25 minutes, or until the top is golden brown and the mixture is bubbling around the edges. Remove from the oven and allow it to rest for a few minutes before serving.

Servings and timing

Prep Time: 15 minutes
Cooking Time: 25 minutes
Total Time: 40 minutes
Servings: 6 servings
Approximate Calories: 520 kcal per serving

Variations

For a heartier version, add 2 cups of cooked pasta such as penne or macaroni before baking to turn it into a tuna pasta bake.

You can swap frozen peas and corn for mixed vegetables, sautéed mushrooms, or steamed broccoli for different flavor combinations.

For extra crunch, sprinkle breadcrumbs mixed with a tablespoon of melted butter over the cheese before baking.

If you prefer a lighter version, substitute thickened cream with additional milk and reduce the cheese slightly.

You can also add a pinch of paprika or dried herbs like thyme or parsley to enhance the flavor.

Storage/Reheating

Store any leftovers in an airtight container in the refrigerator for up to 3 days.

To reheat, place a portion in the microwave and heat in 1-minute intervals, stirring gently in between, until warmed through.

For oven reheating, cover the baking dish with foil and warm at 170°C for about 15–20 minutes, or until heated thoroughly.

This dish can also be frozen for up to 2 months. Allow it to cool completely before wrapping tightly. Thaw overnight in the refrigerator before reheating.

FAQs

Can I use tuna in oil instead of springwater?

Yes, you can use tuna in oil. Just make sure to drain it well to avoid making the sauce too oily.

Can I make this dish ahead of time?

Yes, you can assemble the dish a day in advance, cover it tightly, and refrigerate. Bake it just before serving.

How do I prevent lumps in the sauce?

Whisk continuously while gradually adding the milk and cream to the roux. Adding the liquid slowly helps maintain a smooth texture.

Can I use a different type of cheese?

Yes, cheddar, mozzarella, or a blend of melting cheeses work well in this recipe.

Is this recipe suitable for freezing?

Yes, it freezes well. Cool completely before freezing and store in an airtight container.

Can I add pasta to this recipe?

Absolutely. Stir in cooked pasta before baking to transform it into a tuna mornay pasta bake.

What can I serve with tuna mornay?

It pairs well with a simple green salad, steamed vegetables, or crusty bread.

How do I know when it’s done baking?

The top should be golden and bubbling around the edges. A light golden crust indicates it’s ready.

Can I make it gluten-free?

Yes, substitute the plain flour with a gluten-free flour blend designed for thickening sauces.

Why is my sauce too thick?

If your sauce becomes too thick, whisk in a small amount of warm milk until you reach the desired consistency.

Conclusion

Creamy Baked Tuna Mornay with Golden Cheese Crust is a timeless comfort dish that combines rich, cheesy goodness with tender tuna and vegetables. It’s simple enough for weeknight dinners yet satisfying enough to serve to guests. With its creamy texture, golden topping, and versatile variations, this recipe is sure to become a regular favorite in your kitchen.

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