Skip to Content

Mum’s Easy Tuna Mornay Recipe

This post may contain affiliate links. Read the full disclosure

Mum’s easy Tuna Mornay recipe is a family favourite and a staple meal plan recipe for the whole family. This classic tuna casserole is just like mum used to make. Keep it simple or try one of the many recipe variations with rice, pasta and more to mix things up a little!

Easy tuna mornay recipe

This recipe was first published in April 2015 and updated in 2020.

Mum’s Tuna Mornay Recipe

Growing up, my mum would make tuna mornay as one of the regular family favourites. So cheesy and perfect as a winter comfort food. We now use this same tuna mornay recipe to slot into our own family meal rotation.

Unlike many of the tuna mornay recipes you will find, this one is basic and does not have any pasta included. However, I have shared a few simple recipe variations below, using extra ingredients.

We really do keep it super simple usually, served with toast as a quick and easy mid-week dinner. Even the kids enjoy it, so you know it’s a winner!

Easy tuna mornay recipe

How To make Tuna Mornay

This recipe only takes around half an hour to make, using ingredients you likely already have in your pantry and refrigerator! It takes those boring tins of tuna and turns them into a hearty meal to feed a crowd. Let’s take a closer look at the ingredients and steps to make this easy tuna mornay classic recipe!


  • Butter – You can substitute the butter for margarine instead. A half a cup is needed to make the mornay sauce.
  • Milk – For a healthier tuna mornay recipe, use low-fat milk (and cheese) and it will still taste just as great.
  • Grated cheese – You can use most standard cheeses for your recipe, with half going into your sauce and the other half to be sprinkled on top. Growing up, mum always used the Kraft cheese blocks that were kept in the non-chilled aisle. They are hard to get these days so we usually use tasty or mozzarella cheese instead. You can add a sprinkle of parmesan on top if you like too.
  • Plain All-Purpose Flour – A half a cup of flour is used to thicken the mornay sauce.
Keens mustard
  • Mustard – We use Keen’s mustard powder for our mornay sauce recipe. You can substitute for a different mustard powder or use pre-made mustard such as French or
  • Tinned tuna – Tuna in springwater is my preferred choice for cooking and in general.
  • Salt & pepper – To season your mornay sauce.
  • Breadcrumbs – The breadcrumbs are my favourite part, sprinkled on top and baked until golden in the oven. This gives the tuna mornay the perfect extra texture.
  • Extra butter – Dotted on top of your tuna casserole before adding to the oven will help brown the cheese and breadcrumbs without burning.

Making the Tuna Mornay

STEP ONE – On medium heat, melt half a cup of butter in a saucepan. Then add half a cup of flour gradually while stirring, until blended.

STEP TWO – Boil the butter and flour mix for one minute, then stir in 4 cups of milk slowly. Continue stirring until the sauce boils and thickens. Remove from heat.

Making tuna mornay sauce

STEP THREE – Add salt, pepper, 1-2 teaspoons of mustard, half of the grated cheese and two large tins of tuna. Mix well, breaking apart larger tuna pieces as you stir.

STEP FOUR – Pour your tuna mornay into a casserole dish. Sprinkle the remaining cheese on top, layer with breadcrumbs and dot with butter.

Top with cheese, breadcrumbs and butter

STEP FIVE – Place in moderate oven (180 degrees Celcius fan-forced) and bake for approximately 10 minutes or until the top is golden and the cheese has melted completely. Serve and enjoy!


There are so many variations of tuna mornay recipes. The basic recipe included above is how my mum made it and how we usually make it, served on its own with nothing but toast on the side. We love to dip our toast into the mornay and this is fun for the kids too. But here are some other variations to try:

Salmon Mornay

You can substitute the tuna for salmon if you prefer. I’m not a big salmon fan but my husband loves salmon mornay.

Use tinned salmon instead of tinned tuna and otherwise follow the same recipe as above. You could also mix in other types of seafood for a seafood mornay, or chicken too.

Tuna Mornay Pasta Bake

One of the most common variations is tuna mornay with pasta. Using penne, seashells or spiral pasta, cook on the stove following the pasta cooking instructions while you follow the steps above for your mornay.

Then either mix the drained, cooked pasta through your mornay at step three. Or put your pasta in the bottom of your casserole dish and pour the mornay over the top. You can also serve the pasta directly onto the plate and place your mornay bake on top.

This is a great way to make your recipe go even further if you have a large family or are serving dinner for a crowd.

Tuna Mornay With Rice

Instead of pasta, cook your rice using your typical rice cooking methods and serve either on the side or with your tuna mornay on top.

Adding Vegetables To Tuna Mornay

As a parent or anyone who wants to increase their own vegetable intake, adding vegetables to your mornay is a great way to do this. Corn is a perfect option to mix through your tuna mornay mixture before baking.

Or diced zucchini is another great option. You can even just add a layer of zucchini slices to the top of your bake before you add the cheese and breadcrumbs. Not so hidden vegetables for a healthier dinner!

Easy tuna mornay recipe in a bowl

Storing and Freezing

You may want to double the recipe so you have leftovers or in case you have a big family. Tuna mornay is perfect for bulk cook ups when freezer cooking and also a good meal planning option as it’s quick and simple to make.

Keep leftovers in a sealed container and reheat in the microwave or oven before serving.

Find more dinner recipe inspiration:

Mum's tuna mornay recipe

Mum's Tuna Mornay

Yield: 6
Prep Time: 15 minutes
Cook Time: 10 minutes
Total Time: 25 minutes

Mum’s Tuna Mornay recipe is a classic family favourite cheesy tuna casserole.


  • 1/2 cup butter
  • 4 cups of milk
  • 2 cups grated cheese
  • 1/2 cup plain flour
  • 1-2 teaspoons mustard
  • 2 large tins of tuna
  • Salt & pepper
  • 3/4 cup Breadcrumbs
  • Extra butter


  1. Pre-heat oven to 180 degrees Celcius.
  2. Melt butter in a saucepan over medium heat. Stir in flour gradually until combined.
  3. Boil butter and flour for one minute, then stir in milk slowly. Continue stirring until the sauce boils and thickens. Remove from heat.
  4. Add salt, pepper, mustard, half of the grated cheese and tuna. Mix well, breaking apart larger tuna pieces as you stir.
  5. Pour into a casserole dish. Sprinkle remaining cheese on top, layer with breadcrumbs and dot with butter.
  6. Place in oven and bake for approximately 10 minutes or until the top is golden and the cheese has melted completely. Serve and enjoy!


Variations: Serve with pasta or rice if you want a thicker texture. This will also make your recipe go much further. Add vegetables such as corn and zucchini.

Substitute tuna for salmon to make a salmon mornay. Or try chicken, other types of seafood or vegetables.

Recommended Products

As an Amazon Associate and member of other affiliate programs, I earn from qualifying purchases.

Did you try this recipe?

Leave a comment or a review below and share a photo #simplifycreateinspire

How to Clean & Descale A Shower Head
← Previous
Teriyaki Chicken Tacos
Next →

Lucy @ Bake Play Smile

Friday 3rd of April 2015

Oh I love tuna mornay so much! Mum always used to make this when I was little. But alas! My hubby isn't a tuna fan so I havent had it for years! Have a lovely Easter - from the Fabulous Foodie Fridays team xx


Friday 3rd of April 2015

I just can't understand why so many people dislike tuna. It's great! Make a big batch just for you :)