This low-carb keto tuna casserole is a healthy and delicious twist on the classic cheesy tuna mornay. With a creamy center, chunky tuna, and a golden crunchy topping, it is sure to satisfy even the pickiest eaters.
This recipe is part of my keto casserole recipes collection where you’ll find my keto pizza casserole, cheesy chicken broccoli and cheese casserole and super easy cauliflower cheese.
Why You’ll Love This Recipe
- Creamy, cheesy flavor: This casserole delivers all the classic flavors you love in a traditional tuna casserole but without the carbs.
- Budget-friendly: The ingredients are affordable and readily available at any grocery store.
- Easy to make: With simple ingredients and straightforward instructions, this casserole is a breeze to prepare.
- Simple ingredients: You likely already have most of the ingredients on hand, making this a convenient weeknight meal.
- Low carb: With just 5 grams of net carbs per serving, this casserole is perfect for those following a keto or low-carb diet.
Ingredients
- 2 ounces of butter
- 1 small onion, diced
- 2 sticks of celery, diced
- 7 ounces of mushrooms, diced
- 2 ounces of cream cheese
- ¼ cup of heavy cream
- ¼ cup of unsweetened almond milk
- ½ cup of mozzarella cheese, shredded
- 3 x 5-ounce tins of tuna in water, well-drained
- ½ teaspoon of salt
- ¼ teaspoon of pepper, ground
- ⅓ cup of cheddar cheese, shredded
- 1 Keto Burger Roll or 1-2 slices of Keto Bread, torn (you can leave this out of the recipe and you’ll still have a cheesy & delicious keto tune bake)
- 1 teaspoon of dried parsley
How to Make Keto Tuna Casserole
- Preheat your oven: to 180C/355F.
- Sauté vegetables: Place a medium-sized saucepan over high heat and add the butter, onions, and celery. Sauté for 5-7 minutes, then add the mushrooms and cook for an additional 5 minutes.
- Prepare the sauce: Add the cream cheese, heavy cream, and almond milk to the saucepan, bring to a simmer, and stir until the cream cheese has melted.
- Combine ingredients: Remove the pan from the heat and stir in the mozzarella cheese, drained tuna, salt, and pepper.
- Assemble the casserole: Spoon the creamy tuna mixture into a casserole dish and top with the cheddar cheese, torn keto bread, and dried parsley.
- Bake: for 15-20 minutes, or until the cheese is melted and bubbly and the bread is golden brown and crunchy.
- Serve: immediately, as is, or with a side of cauliflower rice.
Serving Suggestions
Keto tuna casserole is delicious on its own, but you can also serve it with a side of cauliflower rice, broccoli rice, steamed vegetables, or a simple keto salad.
Storing
Fridge: Store in the fridge for up to 4 days.
Freezer: Freeze for up to 3 months in an airtight container. Thaw out overnight before reading in a medium oven or microwave reheat setting.
Frequently Asked Questions
Yes, you can prepare the casserole up to step 5 and store it in the refrigerator. When ready to serve, bake for 10-15 minutes, or until heated through and the topping is golden brown.
Absolutely! Leftover tuna casserole can be frozen for up to 3 months. Thaw in the refrigerator overnight and reheat in the oven or microwave.
No, the mozzarella, cream cheese and cheddar are key to this recipe but you can certainly add a sprinkle of other cheeses for flavor such as parmesan.
Keto Tuna Casserole (Low Carb Tuna Mornay)
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Ingredients
- 2 ounces butter
- 1 small onion diced
- 2 sticks celery diced
- 7 ounces mushrooms diced
- 2 ounces cream cheese
- 1/4 cup heavy cream
- 1/4 cup unsweetened almond milk
- 1/2 cup mozzarella cheese shredded
- 3 5 ounce Tuna in Water well drained
- 1/2 teaspoon salt
- 1/4 teaspoon pepper ground
- 1/3 cup cheddar cheese shredded
- 1 Keto Burger Bun
- 1 teaspoon dried parsley
Instructions
- Preheat your oven to 180C/355F.
- Place a medium-sized saucepan over high heat and add the butter, onions, and celery. Saute for 5-7 minutes then add the mushrooms.2 ounces butter, 1 small onion, 2 sticks celery, 7 ounces mushrooms
- Cook the mushrooms for 5 minutes then add the cream cheese, heavy cream, and almond milk and bring to a simmer.2 ounces cream cheese, 1/4 cup heavy cream, 1/4 cup unsweetened almond milk
- Once the cream cheese has melted stir through the mozzarella cheese and remove the pan from the heat.1/2 cup mozzarella cheese
- Mix through the drained tuna, salt, and pepper.3 5 ounce Tuna in Water, 1/2 teaspoon salt, 1/4 teaspoon pepper
- Spoon the cream tuna mixture into a casserole dish and top with the cheddar cheese, torn Keto Bread, and dried parsley.1/3 cup cheddar cheese, 1 Keto Burger Bun, 1 teaspoon dried parsley
- Bake for 15-20 minutes until the cheese has melted and the bread is browned and crunchy.
- Serve straight away.
Notes
Nutrition
This low-carb tuna casserole recipe makes four servings.
Store the tuna casserole in the fridge for up to 4 days, or freeze for up to 3 months.
If you enjoy this Keto Tuna Mornay and other one-pan-style meals? Why not try some of our other low-carb casserole recipes
- Keto Cheesy Chicken and Broccoli Casserole
- Keto Loaded Cauliflower Casserole
- One Pan Keto Mexican Casserole
- Keto Breakfast Casserole
To make a larger batch of this Keto Tuna Mornay recipe, adjust the servings in the card below.
