This creamy keto tuna mornay casserole bake recipe is a great budget-friendly low-carb meal that the whole family will love.

Keto Tuna Mornay can be made ahead of time and baked when needed.
To make this tuna mornay ahead of time, pause the recipe at step 6 and store it in the fridge, then cook in the oven for 10 to 15 minutes when needed.
Keto Tuna Casserole Ingredients

- 2 ounces of Butter
- 1 small Onion, diced
- 2 stick of Celery, diced
- 7 ounces of mushrooms, diced
- 2 ounce 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, drained well
- 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
- 1 teaspoon of Dried Parsley
How to Make Keto Tuna Casserole Bake

- 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.
- Cook the mushrooms for 5 minutes, then add the cream cheese, cream, and almond milk to a simmer.
- Once the cream cheese has melted, stir through the mozzarella cheese and remove the pan from the heat.
- Mix through the drained tuna, salt, and pepper.
- Spoon the cream tuna mixture into a casserole dish and top with the cheddar cheese, torn Keto Bread and dried parsley.
- Bake for 15-20 minutes until the cheese has melted and the bread is browned and crunchy.
- Serve straight away as is or with a side of Cauliflower Rice.

Keto Tuna Casserole Bake – Low Carb Mornay
Unit Conversion
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.
- Cook the mushrooms for 5 minutes then add the cream cheese, cream, and almond milk and bring to a simmer.
- Once the cream cheese has melted stir through the mozzarella cheese and remove the pan from the heat.
- Mix through the drained tuna, salt, and pepper.
- Spoon the cream tuna mixture into a casserole dish and top with the cheddar cheese, torn Keto Bread, and dried parsley.
- Bake for 15-20 minutes until the cheese has melted and the bread is browned and crunchy.
- Serve straight away as is or with a side of Cauliflower Rice.
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.