This delicious and filling low carb and keto tuna casserole has no noodles, but it does have lots of flavor! Plus it’s so easy to make.
This low carb keto tuna casserole is so good! It has no noodles, and I promise – you won’t miss them.
It’s a lazy casserole – minimal chopping necessary. And it’s ready fast, so it’s perfect for weeknight dinners.
What are the ingredients in keto tuna casserole?
This is a delicious, filling, well-seasoned mixture of canned tuna, chopped red onion, mayonnaise, and cheese, baked until golden and bubbly.
You can bulk it up by adding 2 cups of cooked riced cauliflower, increasing the mayonnaise to 1/2 cup, and dividing it into 3 servings. But I usually don’t, because my husband and I like the casserole better without cauliflower.
Here’s an overview of the ingredients – exact measurements are listed in the recipe card below:
- Canned tuna
- Avocado oil mayonnaise
- Dijon mustard
- Shredded Gruyere cheese
5, Chopped red onion - Salt, black pepper, and cayenne pepper
- Chopped parsley for garnish
How to make keto tuna casserole
It’s so easy! Scroll down to the recipe card for the detailed instructions. Here are the basic steps:
- Simply mix everything together, reserving part of the cheese and the parsley.
- Then transfer the mixture to a small baking dish.
- Sprinkle with cheese.
- Bake 15 minutes at 400°F.
- Garnish with parsley and serve.
Is it healthy?
I believe it is. It is low carb and gluten-free. I use skipjack tuna in this recipe because it’s lower in mercury than other tuna species.
And I prefer to use avocado oil mayonnaise because I believe it’s healthier than mayonnaise that is based on refined, bleached and deodorized oils (RBD oils).
The cheese, happily, is harmless according to current research and might even be beneficial.
What to serve with keto tuna casserole?
This casserole is rich and filling. As you can see in the recipe card below, a serving has 465 calories. So I simply serve it with fresh-cut veggies for scooping. It’s also good with a side of microwave broccoli.
What to do with leftovers?
Leftovers keep well in the fridge for 3-4 days or freeze them if you want to keep them for longer. Gently reheat them in a 300°F oven, or in the microwave on 50% power.
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Keto Tuna Casserole
INGREDIENTS
- 2 (5oz) cans tuna in water, drained
- 1/3 cup avocado oil mayonnaise
- 1 tablespoon Dijon mustard
- 1/2 cup shredded gruyere, divided
- 1/4 cup chopped red onion
- 1/4 teaspoon sea salt
- 1/4 teaspoon black pepper
- ¼ teaspoon cayenne pepper
- ¼ cup chopped parsley for garnish
INSTRUCTIONS
- Preheat oven to 400 degrees F.
- Mix together the tuna, mayonnaise, mustard, 1/4 cup cheese, onion, salt, pepper and cayenne.
- Transfer the mixture to a small, 1-quart casserole dish. Sprinkle 1/4 cup shredded cheese on top.
- Bake until hot, about 15 minutes. Sprinkle with parsley and serve immediately, with cut-up veggies.
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Vered DeLeeuw, LL.M., has been following a healthy real-food diet and blogging about it since 2011. She has taken 
