
Why You Will Love This Recipe
Comfort food – this canned tuna casserole is hearty and takes many of us back to our childhood.
Quick and easy – this tuna mornay without pasta uses simple ingredients, and is on the table in under 30 minutes.
Simple ingredients – all the ingredients are basic, regular pantry and fridge items.
Low carb – at only 5g net carbs per serve, this is an ideal low-carb and keto-friendly main meal.
Family-friendly! – This is a keto meal that will be enjoyed by the whole family.
Various cooking methods – I have included methods to air fry, grill, or oven bake. Thermal cooking methods for our Thermomix® users have been included for the sauce too.
What is Tuna Mornay?
A tuna mornay is a classic recipe that has been around for a very long time. In Australia Tuna Mornay has been a family favourite meal for many decades and served many different ways. I remember my mum making it with a tin of Campbells soup (maybe cream of celery or cream of mushroom).
It is also often referred to as tuna casserole, tuna pasta bake, baked tuna casserole or tuna pie. It is basically a cheesy tuna casserole often served with vegetables and pasta or rice to bulk it out to feed a family cheaply.
This version has no pasta or rice. The ingredients I have used are all gluten-free, and low carb keto friendly. You can add pasta, rice, vegetable noodles (eg. zoodles) as you prefer. It is simple and delicious and very versatile.
Similar Recipes include – Cauliflower Mac and Cheese / Keto Salmon Patties
The Ingredients
Scroll to the recipe card at the bottom for the quantity of each ingredient used and the full detailed recipe on how to cook tuna mornay! Keep reading for more details on the ingredients, substitutes and step by step instructions on how to make it.

The ingredients used in a tuna casserole pasta bake can vary but here is what we use for this simple and quick version.
Tuna – I just use cheap canned tuna. You can use tuna in springwater, brine or oil. The choice is yours. Fresh tuna that has been cooked and flaked can be used if you prefer.
Cream – thickened or heavy cream is best. See below for substitutions if you need a dairy free tuna mornay recipe.
Cheese – pre-shredded mozzarella, cheddar, or any sharp flavoured tasty cheese can be used. You can also substitute parmesan if you prefer.
Vegetables – I have used mushrooms and zucchini for the main vegetables. You can use any vegetables you have on hand like pumpkin, broccoli, spinach, cauliflower or just about anything. Honestly, this recipe is so flexible.
Variations
- Swap tuna with canned salmon, chicken, bacon, or ground beef or sausage. Use marinara mix or even just all vegetable if you prefer.
- for dairy free tuna casserole swap the cream for cauliflower soup or your favourite dairy free cream or milk alternative. Or use canned tomatoes instead. Another popular option is to make tuna casserole with mayonnaise. Mayonnaise adds a creaminess to a tuna casserole without the dairy. The cheese can be replaced with nutritional yeast.
- Vegetables are easily swapped to anything you have on hand to keep it simple. Often served with peas, corn, pasta, rice or potatoes.
- Add seasoning, spice, or more fresh herbs. The creamy tuna sauce would be perfect with our Ranch Seasoning, Italian Seasoning or even curried tuna casserole would be amazing!
- Use leftover Christmas ham, rotisserie chicken, or turkey in place of turkey!
- Crunchy Toppings – I used to do this with crispy baked cheese crumbled on top. Before I followed the keto lifestyle I used to top tuna bake with crisp chips crumbled on top. It was so good. So crispy cheese is a great alternative.
How to Make It


Step 1. Preheat the oven to 200℃ FAN/220°C STATIC/425°F. Heat the butter in a saucepan over medium heat (I use a skillet or cast iron pan that I can transfer to the oven). Sauté the onions and mushrooms.
Step 2. Add the zucchini and sauté for 1 minute.


Step 3. Add the tuna, cream, and cheese and cook stirring occasionally until it begins to thicken.


Step 4. Top with remaining cheese and bacon and bake for 10 minutes or until golden and crispy on top.

Step 5. Serve as is or serve with a side of grilled asparagus or broccoli.
Thermomix Tuna Casserole
I have also included a method to make tuna mornay in a Thermomix. I still finish off baking it in the oven but you could also steam it if you prefer and brown it with a butane torch.
I do tend to find that creamy based sauces dont reduce quite as much when cooking in a thermal cooker. You may need to extend the time in the oven to reduce the sauce (if you prefer). See the recipe card below for the full method and tips.
FAQS and Hot Tips
Keep in the fridge for 2-3 days.
You can freeze tuna casserole and thaw in the fridge overnight before reheating. This can be done before or after baking.
You sure can! You can mix all the ingredients into the base of a slow cooker or crockpot and cook o low for 3 hours. Turn the heat up to high before serving and top with cheese and bacon.
More Recipes To Try
If you love our low carb tuna casserole and want more cheap family meals then here are just a few.
- Beef Stew Recipe
- Devilled Sausages
- Keto Chicken Enchiladas
- Schweinshaxe – Bavarian Slow Cooked Pork Knuckle
- Easy Zucchini Slice

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Tuna Mornay
Ingredients
- 2 tablespoons butter
- 1/4 onion diced
- 100 g mushrooms sliced
- 200 g zucchini chopped or spiralised
- 220 g thickened cream or heavy cream, see notes
- 100 g mozzarella cheese
- 400 g tinned/canned tuna
- 1 rasher bacon cut into thin strips
- 1 green onion or chives chopped
- 1 tbsp parsley chopped
Instructions
CONVENTIONAL METHOD
- Preheat oven to 200℃ FAN/220°C STATIC/425°F.
- Melt butter in an oven-safe pan over medium heat. Sauté onion and mushrooms until soft. Add zucchini and stir through. Add cream, half the mozzarella, and tuna. Stir until it begins to thicken. Season with black pepper.
- Top with remaining cheese, and bacon. Transfer to oven; bake 8-10 minutes until golden. Top with green onions, chives, and parsley. Serve.
THERMAL METHOD
- Preheat oven to 200℃ FAN/220°C STATIC/425°F.
- Heat butter 2 min/100℃/speed 2.
- Add onion and mushrooms; cook 5 min/120°C/reverse/speed 1. Add zucchini, and cream; cook 8 min/100°C/reverse/centre cap off/speed 1. Stir through half the mozzarella and add the tuna. Season with black pepper. Pour into a baking dish or cast iron pan.
- Top with remaining cheese, and bacon. Transfer to oven; bake 8-10 minutes until golden. Top with green onions, chives, and parsley. Serve.
Notes
All recipes have been tested using all of the cooking methods included by various recipe testers.
Your Own Notes
Nutrition
48 responses to “Easy Tuna Mornay”
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I’ve never made tuna mornay before and this recipe was so easy to follow and it came out perfect and delicious! -
We just loved this dish! The tuna was great with the bacon, and that creamy sauce added a decadent touch. Definitely a winner for us!-
Yay! So happy it was a winner
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This tuna is such a classic comfort food-
It sure is
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I’ve never heard of tuna mornay, but this looks delicious! I’ve never thought to add bacon to tun before, but now I want to try this. Thanks as always for another delicious winner!-
You are very welcome Genevieve
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This tuna mornay was so delicious! I loved the addition of the salty bacon! Yum!-
Me too Kayla
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What a beautiful dish!! I think even my picky husand will like this!!
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I sure hope he does
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This was so good! Even the non-tuna lovers in our family enjoyed it!-
I am so happy it turned out well for everyone
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The BEST comfort food – the bacon is such a good addition. So tasty!-
It sure is
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Love this recipe. I didn’t have any bacon but it was still delicious. I will definitely make it again. -
Made this dish last night whole family loved it. It’s a keeper. -
Loved the finished dish.
Just a couple of queries though. Recipe doesn’t say when to put parsley in, assuming mozzarella is grated and tuna drained. -
Yummy will be doing this one
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I have made this dish a couple of times now. We love how quick and easy it is. I changed the tuna for white fish ( barramundi) and added some green prawns chopped into pieces. I took the skin off the fish and crisped it up and and added on top of dish when it was out of the oven. Served it with zoodles and salad.
The second variation was cooking the fish pieces and using the mornay sauce as a topper and served with a green salad. Either way delicious and will be making again. It’s a great recipe . -
Unfortunately not a winner with my family – hubby & I liked it but the kids – no way 🙁 -
This is my all time favourite!! Weekly staple!! Plus sooo easy to make!! Highly recommend for everyone to try!! 🙂 <3 -
Tuna Mornay reigning in from the 80’s and 90’s – this is delicious – i didn’t have mushrooms or spring onions so subbed with capsicum and brown onion and sautéed for a bit longer. Winner in our house ever with non Mr. LCHF! Loved the bacon and cheese topping!
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Best recipe absolutely love it. My dad who hated tuna even eats it. -
We loved this. Had great flavour. Will be making again -
This is probably a favourite recipe in the Keto cookbook with my family. It is made almost weekly .. even my fish hating daughter devours this meal .. thanks Megan for giving me a recipe we can all eat and enjoy x
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Bowls licked clean, and asked to make again….Success!
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