Keto Tuna Casserole | One of The Best Keto Casserole Recipes

This keto tuna casserole is made with mushrooms and spinach and is packed with two types of cheese - making it the ultimate cheesy tuna casserole! And it's not only flavorful & creamy, but it's nutritious too. Honestly, this might just be one of the best keto casserole recipes you can make.

THE BEST KETO TUNA CASSEROLE

This low carb tuna casserole has everything that makes a great keto recipe.

It filled with keto-friendly vegetables, creamy melted cheese, has a ton of flavor, and yields multiple servings. 

And of course, it's a low carb tuna casserole! There's only 3 NET CARBS per serving.

Also, this keto tuna casserole is loaded with nutrients and it is gluten free, making it a super healthy meal. 

Tuna is not only a great source of protein but it's also an excellent way to get your daily dose of omega-3 fatty acids and vitamin B6. Top that off with the mushrooms and spinach, and you've got yourself one super healthy dish. 

Plus, this low carb keto recipe is incredibly quick and easy to make, and you can have it ready and on the table in under 30 minutes. 

Oh, and if you're looking for more low carb casseroles, check out this asparagus casserole and cheesy spinach casserole next!

INGREDIENTS FOR KETO TUNA CASSEROLE

Now, typically, tuna casserole is made with bread crumbs and noodles, causing the dish to have upwards of 60 grams of carbs per serving. 

For this low carb tuna casserole though, we will be using almond flour in place of bread crumbs to keep the carbs down but still give this casserole a crispy, crunchy surface, just like with these keto chicken nuggets. 

Also, we'll be using mushrooms instead of noodles to make this recipe even more low carb and gluten free. 

Having said all of that, here's the complete list of things you'll need to make this low carb keto casserole:

• 2 tbsps butter 
• ½ onion, chopped 
• 2 cups sliced mushrooms
• 1 cup chopped spinach
• 2 five ounce cans of tuna packed in water, drained
• 1 cup grated mozzarella cheese 
• 1 cup cream cheese, cubed
• 1 teaspoon Italian seasoning
• Salt and pepper to taste
• 2 cups shredded Cheddar Cheese 
• 2 tbsp almond flour

Combining the ingredients in this recipe makes this casserole irresistibly delicious and turns regular tuna casserole into super healthy comfort food.

And it's easy to make, and even easier to clean up.

So you know I'm a big fan of that.

GRATE YOUR OWN CHEESE 

We are going to be using mozzarella and cheddar cheese to give this tuna casserole its delicious cheesiness. 

Although both of these cheeses come pre-shredded, I recommend shredding your own cheese with a cheese grater. 

The pre-shredded cheeses that you can buy at the store typically have added starches in them. 

The added starches prevent the cheese from clumping and sticking together. But, these starches contain unnecessary carbohydrates.

So, to keep your keto tuna casserole - and other low carb recipes - as low carb as possible, avoid the pre-shredded kind. 

Now, if you already have the pre-shredded cheese on hand or don't want to buy a block of cheese, don't worry. This dish is already super low in carbs, thanks to the rest of the ingredients, so feel free to use it.

By the way, to make this even cheesier, you can sprinkle some parmesan cheese on top after it gets out of the oven.

ARE MUSHROOMS KETO?

As I mentioned earlier, we will be using mushrooms in place of noodles for this tuna casserole. 

Now, mushrooms tend to get overlooked and not many people realize just how great they are for keto. 

In fact, mushrooms might be the best low carb keto "vegetable" you can have.

First off, mushrooms are super low in calories and carbs. Each cup has about 16 calories and a low carb count - about 1.5 grams.

Secondly, mushrooms are packed with fiber and water, making them a "bulk" food. And this means that they can make you feel full without eating a lot of them.

Plus, mushrooms are high in potassium, which is an essential mineral and electrolyte. And potassium is vital on the keto diet because your body flushes out a lot of water since you are not eating carbs to retain it. 

So, the verdict is that mushrooms are keto friendly, and one of the best keto foods you can eat. 

Mushrooms to use for this casserole

Ok, so we know mushrooms are perfect for this low carb tuna casserole, but what mushrooms should you use?

There are various mushrooms to choose from, and you really can use any ones you want.

With that said, I suggest using sliced white or brown button mushrooms, cremini mushrooms, or mini-portobellos.

I think these mushrooms pair best with the overall flavor in this tuna casserole. 

HOW TO MAKE KETO TUNA CASSEROLE

Ok, so now let's get into the nitty-gritty on how to make this low carb keto casserole.

One of the reasons I love this gluten free casserole is that it only requires a few steps and it is so quick and easy to make.

All you have to do is sauté the vegetables, incorporate the rest of the ingredients, then bake everything in the oven, and you'll have yourself a delicious casserole ready to go. 

Now, if you're ready to make this recipe, let's get to it!

STEP 1: PREP

First off, you'll want to preheat your oven to 350°F (176°C) and coat a 9x13 baking dish with cooking spray.

Next, you'll want to prepare the vegetables. Chop the spinach and onions, then slice the mushrooms. 

STEP 2: SAUTE THE VEGETABLES

Now we're all set to start sauteing our vegetables.

So, to begin the sauteing process, you'll want to melt the butter in a large pan over high-heat. 

Next, add the onions and saute for 3 minutes. Then, once the onions have softened, add the mushrooms.

Cook the mushrooms for about 5 minutes on high-heat to reduce the moisture in them. And make sure you stir the mushrooms often while cooking.

Lastly, add the spinach, stir them until they're wilted, and turn the heat down to low.

STEP 3: COMBINE ALL THE INGREDIENTS

Now you're all set to add the cream cheese, grated mozzarella, Italian seasoning, salt, and pepper to the pan.

Cook everything and stir until the cheese just starts to melt and combines with the other ingredients.

After that, add the drained tuna and stir together until everything is combined. 

STEP 4: ASSEMBLE AND BAKE

So, at this point, you'll want to spoon the tuna mixture evenly into the baking dish. 

Then, sprinkle the shredded cheddar on top, followed by the almond flour.

Bake for a total time of 15-20 minutes, or until the surface is crisped and golden brown.

Let it cool for a few minutes in the baking dish, sprinkle some parmesan cheese on top, and then this casserole is ready to serve!

STORING YOUR KETO TUNA CASSEROLE

While low carb tuna casserole is best enjoyed fresh, this recipe makes about 10 servings, giving you a delicious leftover meal for the next few days. 

You can store your leftovers in an airtight container in the refrigerator for up to 3 days. If your baking dish has a lid to it, simply pop it on and put the casserole dish in the fridge. 

For reheating the refrigerated casserole, put it in the oven at 350° F (176°C) until warm, about 20-30 minutes, then sprinkle some grated parmesan on top and dig in!

FREEZING YOUR CASSEROLE 

You also have the option to freeze this casserole if you would like for it to last longer.

It can be frozen for up to 6 months, as long as you store it in an airtight, freezer-safe container.

To reheat the casserole that has been frozen, you have two options. 

First, you can let it thaw in the fridge, then reheat in the oven at 350°F (176°C) for about 20-30 minutes until it reaches your desired temperature. 

However, you can also reheat frozen tuna casserole directly in the oven, though this will take significantly longer, sometimes up to an hour.

Just make sure that you let your frozen tuna casserole come to room temperature before popping it in the oven to avoid the dish's glass breaking due to extreme temperature change.

Also, it can be reheated in the microwave, but you may lose some of the crunchiness on the surface layer you get when baking and reheating in the oven.

NUTRITIONAL INFORMATION

As I mentioned above, this gluten free and keto tuna casserole has just 3 NET CARBS per serving. Pretty good for a dish that traditionally has a super high carb count.

So, this recipe makes a 10 serving casserole, but the full nutritional information for 1 serving is as follows:

• 239 Calories
• 19g Fat
• 4g Carbs
• 1g Fiber
• 3g NET CARBS
• 14.4g Protein

Now, since this recipe makes so many servings, it is a great meal to make and have on hand for lunch or dinner the next couple of days. Meal prep anyone?!

Or, if you want to make this dish for a family dinner, you'll easily be able to feed everyone.

And trust me, they'll enjoy this low carb tuna casserole just as much as a non-keto tuna casserole. 

Anyway, I hope you like this keto tuna casserole as much as I do, and if you try it out, let me know what you think in the comments below.

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