Old-Fashioned Tuna Mornay with Crunchy Chip Topping

There’s something very comforting about a simple baked pasta dish, especially one that comes together with pantry ingredients. Tuna Mornay has been a family favourite for generations, and it’s easy to see why. It’s creamy, filling, and stretches well to feed a family.

This version uses tinned tuna and a simple homemade cheese sauce. It also has a crunchy potato chip topping that gives the casserole a lovely bit of texture. It’s an easy dinner to put together. It’s a fantastic way to transform a few everyday ingredients into a proper family meal.

This recipe is also part of a series on my YouTube channel called Old Fashioned Dinners (That Still Work Today). In this series, I’m sharing classic family meals. Many of us grew up with these meals. They are simple and comforting dinners and still work beautifully in modern kitchens.

Watch the Episode

In this episode of Farmers Wife Homestead, I make Tuna Mornay. It is a classic baked pasta dish with creamy sauce, tuna, and a crunchy potato chip topping.

New episodes in this series are shared every Sunday evening at 7 pm (NZST) on YouTube. They are uploaded alongside my usual Wednesday uploads.

Tuna Mornay – Old Fashioned Dinners Series Episode Four

Previous Episodes in the Series

If you’re following along with this series, you might also enjoy the earlier episodes:

Each of these recipes is another example of a classic dinner that still works beautifully in modern kitchens.

• Old-Fashioned Fish in Parsley Sauce – Episode 1
• Bangers and Mash with Onion Gravy – Episode 2
• Savoury Mince with Focaccia – Episode 3

Other Recipes You May Like

• Hearty Savoury Mince with Potatoes & Vegetables
• Cheesy Loaded Chips/Wedges | Easy Air Fryer Snack Everyone Loves
• 15-Minute Creamy Chicken & Bacon Pasta
• From Garden to Table: Homemade Tomato Pie

Recipe Card

Serves: 4–6
Prep time: 15 minutes
Cook time: 25 minutes

Ingredients

1 × 425 g tin tuna in spring water, drained
500 g cooked pasta (any shape – spirals work well)
½ cup frozen peas
50 g butter
¼ cup plain flour
3 cups milk
1 tsp onion powder
1 tsp garlic powder
1 Tbsp lemon juice
3 cups grated cheese
salt and pepper to taste

For the topping

50 g butter, melted
150 g bag plain salted potato chips (crisps), crushed

Method

1. Preheat the oven to 180°C.
2. Melt the butter in a large pan over medium heat. Add the flour and whisk for about a minute to cook the flour.
3. Gradually add the milk, whisking continuously until smooth. Add the onion powder and garlic powder and continue cooking until the sauce thickens.
4. Stir in the lemon juice and season with salt and pepper.
5. Add the grated cheese and frozen peas and stir until the cheese has melted. Remove from the heat.
6. Gently stir in the cooked pasta and drained tuna, keeping the tuna pieces slightly chunky.
7. Spoon the mixture into a casserole dish.
8. In a bowl, mix the melted butter with the crushed potato chips.
9. Sprinkle the chip topping evenly over the pasta.
10. Bake for 20–25 minutes until golden and bubbling. Serve hot.

What to Serve with This Recipe

Tuna Mornay is already a hearty meal, but a few simple sides work well with it:

• Steamed broccoli or green beans
• A fresh garden salad
• Buttered carrots
• A slice of homemade Focaccia (see my recipe here)

Stacey’s Kitchen Tips

• If you already have leftover pasta in the fridge, this recipe comes together very quickly.
• Try not to break the tuna up too much when mixing. Leaving it in larger pieces gives the dish a nicer texture.
• The crushed potato chip topping sounds unusual, but it adds a lovely crunch and extra flavour too.

Variations & Substitutions

This is a flexible recipe and easy to adapt:

• Swap peas for corn or mixed vegetables.
• Use any short pasta shape like penne, shells, or macaroni.
• Add a little mustard powder to the sauce for extra flavour.
• If you prefer a traditional topping, use buttered breadcrumbs instead of potato chips.

Storage, Freezer & Make-Ahead Notes

• Leftovers keep well in the fridge for up to 3 days in a covered container.
• Reheat portions in the microwave or warm the casserole in the oven until heated through.
• You can also assemble the dish ahead of time and keep it in the fridge before baking. Add the topping just before it goes into the oven.

Final Thoughts

Tuna Mornay is one of those simple dinners that’s stood the test of time. It’s filling, economical, and easy to make with ingredients most of us already have in the pantry.

If you enjoy comforting, old-fashioned meals, this one is well worth adding back into your regular dinner rotation.

Stacey