This Keto Tuna Casserole is the perfect low-carb comfort food! This dish is only 3.4 net carbs and packed with zucchini noodles, a creamy cheese sauce, and chunks of tuna.

keto tuna casserole in a large glass baking dish

 

If you loved my super popular Taco Zoodle Casserole you are going to love this Keto Tuna Zoodle Casserole! It has tons of zoodles and that same rich creamy cheese sauce along with tender chunks of tuna. It is a delicious low-carb comfort food even your picky eaters will love!

Believe it or not, I am a total carb junkie. Have you seen that episode of Friends where Monica tells Rachel she has to do something because she owes it to her inner fat girl, then she says “I owe this to her, I never let her eat!” that is my relationship with carbs. I love them, but they just don’t love me.

One of my favorite things was a good cheesy pasta or rice casserole. This Cheesy Chicken and Rice was my particular indulgence in my pre-keto days. Sadly, those dishes are a thing of the past around here, but this Keto Tuna Casserole is a great low-carb replacement! 

I asked on Instagram what most people struggled with on keto and one overwhelming answer was that you miss old favorites. This resonated with me because I struggle with this too. I think sometimes when you’ve had a long day and your tired you just want those comfort foods.

I wanted to recreate some of those good old classic flavors from dishes most of us grew up knowing and loving. So this healthy tuna casserole is my first in a long list of keto comfort foods! This dish is packed with zucchini noodles (I have a trick to prevent them from being soggy and watery!) a creamy cheese sauce and chunks of tuna.

low carb tuna casserole being spooned out of the baking dish

What’s in Keto Tuna Casserole? 

To make this cheesy tuna noodle casserole, all you need is: 

  • Zucchini- if you aren’t a fan of zucchini, use spaghetti squash!
  • Butter
  • Garlic
  • Unsweetened almond milk
  • Heavy cream
  • Cream cheese
  • Cheddar cheese
  • Canned tuna
  • Mozzarella cheese 

How to Make Keto Tuna Casserole

Making tuna casserole from scratch is so much easier than you’d think! No need to buy “cream of” soups at the store for this low-carb version. 

  1. Lightly spray the bottom of a 9×13-inch baking dish with cooking spray.
  2. Place the zoodles in the dish and spread out as much as possible.
  3. Bake at 10-minute intervals. Remove and stir every 10 minutes, and continue baking at 10-minute intervals until the moisture has evaporated. 
  4. While the zoodles are baking, make the cheese sauce. Stir in drained tuna. Remove from heat.
  5. In the 9×13-inch pan you pre-baked your zoodles in, layer the zoodles, tuna cheese sauce, and remaining shredded cheese to the top.
  6. Bake until gold and bubbly.

cheesy keto tuna casserole being spooned out of a glass baking dish

How Many Carbs Are in This Dish? 

This dish is only 3.4 net carbs per serving and it is so satisfying. 

Can I Add Veggies? 

If you’re not concerned with keeping this homemade tuna casserole low-carb / keto, you’re welcome to add in veggies. I’ve seen traditional tuna casserole recipes use frozen peas and finely diced celery. If you don’t enjoy zucchini, feel free to substitute for spaghetti squash.

Tips for Making Low-Carb Tuna Casserole 

  • If you want to add a keto-friendly crunchy topping, just sprinkle some crushed pork rinds on top. It keeps the net carb count ultra low and will help give you that crunchy texture.
  • Shredded chicken works great in this dish if you want to switch things up!
  • Make sure to use unsweetened almond milk, not flavored or sweetened. 

More Keto Comfort Food Recipes: 

This Keto Tuna Zoodle Casserole is the perfect low carb comfort food! This dish is only 3.4 net carbs and packed with zucchini noodles, a creamy cheese sauce and chunks of tuna. #keto

Get the Recipe: Keto Tuna Zoodle Casserole

This Keto Tuna Casserole is the perfect low-carb comfort food! Only 3.4 net carbs and packed with zoodles, creamy cheese sauce, and tuna.
4.51 from 265 ratings

Ingredients
 

For the Zoodles:

  • 3 medium zucchini, spiralized

For the Cheese Sauce:

For the top:

  • 1/2 cup cheddar cheese
  • 1/2 cup mozzarella cheese

Equipment

  • Brieftons 5-Blade Spiralizer (BR-5B-02): Strongest-and-Heaviest Duty Vegetable Spiral Slicer, Best Veggie Pasta Spaghetti Maker for Low Carb/Paleo/Gluten-Free, With Extra Blade Caddy & 4 Recipe Ebooks

Instructions
 

  • Preheat oven to 350 degrees F.
  • Lightly spray the bottom of a 9x13-inch baking dish with cooking spray.
  • Place the zoodles in the dish and spread out as much as possible.
  • Bake zoodles at 10-minute intervals. Remove and stir every 10 minutes, continue baking at 10-minute intervals until the moisture has evaporated. **(see note below)
  • While zoodles are pre-baking, heat a medium size skillet over medium heat. Melt the butter, then add the garlic, almond milk, heavy cream, cream cheese and 1 cup of the cheddar cheese. Whisk mixture until it is smooth and cheese has melted.
  • Stir in drained tuna. Remove from heat.
  • In the 9x13-inch pan you pre-baked your zoodles in, layer the zoodles, tuna cheese sauce, and remaining shredded cheese to the top.
  • Bake 25-30 minutes until gold and bubbly.

Notes

  • Zoodles: Depending on the size and moisture level of the zucchini this may take between 10-20 minutes. Remove when moisture as evaporated and they have shrunk in size, but before they are brown or crispy.
  • Shredded chicken works great also if you want to switch things up!
  • This recipe yields 6 servings. Each serving is roughly 1 1/2 cup and has 3.3 net carbs. 
Serving: 1.5 cups (roughly), Calories: 295kcal, Carbohydrates: 3.4g, Protein: 23.4g, Fat: 20.6g, Cholesterol: 80.4mg, Sodium: 522mg, Fiber: 0.1g
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