Keto Diet App - Free Download Keto Diet App - Free Download
Take the guesswork out of following a low-carb diet, lose body fat & feel great!
KetoDiet app is FREE to download!

Cheesy Low-Carb Tuna Casserole

4.5 stars, average of 165 ratings

This post may contain affiliate links, see our disclaimer.

Cheesy Low-Carb Tuna CasserolePin itFollow us 148.4k

Comfort food for my partner is anything hot and cheesy, while eating too much heavy, cheesy foods often leave me feeling heavy. This keto recipe is the perfect balance for us, with creamy cheesy sauce spooned through lots of vegetables and canned tuna.

I usually use broccoli and cauliflower but you could use whatever you have on hand, including any frozen vegetables. Likewise, I like tuna here, but you could swap out for another fish — either tinned, smoked, or cooked salmon, sardines or mackerel — all would work. If you're not a fan of fish, feel free to use cooked chicken or turkey.

This recipe will make 4 regular-small servings or 2-3 generous servings. Enjoy!

Hands-on Overall

Serving size about 255 g/ 9 oz

Allergy information for Cheesy Low-Carb Tuna Casserole

✔  Gluten free
✔  Egg free
✔  Nut free
✔  Nightshade free
✔  Pork free
✔  Avocado free
✔  Coconut free
✔  Shellfish free
✔  Beef free

Nutritional values (per serving, about 255 g/ 9 oz)

Net carbs5.8 grams
Protein29.6 grams
Fat22.6 grams
Calories342 kcal
Calories from carbs 7%, protein 34%, fat 59%
Total carbs8.1 gramsFiber2.3 gramsSugars3 gramsSaturated fat13.3 gramsSodium528 mg(23% RDA)Magnesium50 mg(13% RDA)Potassium550 mg(27% EMR)

Ingredients (makes 4 servings)

  • 1/2 head broccoli (200 g/ 7.1 oz)
  • 1/2 head small cauliflower (200 g/ 7.1 oz)
  • 1 large can of tuna, drained (375 g/ 13.2 oz)
  • 1 recipe Keto Cheese Sauce (makes about 1 cup/ 240 ml)
  • 3/4 grated mozzarella cheese or cheddar (85 g/ 3 oz)


  1. Preheat oven to 180 °C/ 355 °F (conventional), or 160 °C/ 320 °F (fan assisted).
  2. Chop the broccoli and cauliflower into small florets and steam until just tender. Set aside to cool slightly. If you're using frozen and thawed vegetables, you won't have to cook them. Cheesy Low-Carb Tuna Casserole
  3. Add the vegetables and tuna to a large ovenproof dish and pour over the sauce, then gently stir through.
    Cheesy Low-Carb Tuna Casserole
  4. Sprinkle with the cheese.
    Cheesy Low-Carb Tuna Casserole
  5. Bake 15 minutes or until golden on top.
    Cheesy Low-Carb Tuna Casserole
  6. Serve or let it cool down and store in the fridge up to 5 days. Reheat before serving.
    Cheesy Low-Carb Tuna Casserole

Ingredient nutritional breakdown (per serving, about 255 g/ 9 oz)

Net carbsProteinFatCalories
Broccoli, broccolini, fresh
2 g1.4 g0.2 g17 kcal
Cauliflower, fresh
1.5 g1 g0.1 g13 kcal
Tuna, tinned (in brine), drained
0 g18.2 g0.9 g81 kcal
Keto Cheese Sauce, homemade, basic (KetoDiet blog)
1.1 g4 g17.2 g169 kcal
Mozzarella cheese (low moisture, for pizza)
1.2 g5 g4.2 g63 kcal
Total per serving, about 255 g/ 9 oz
5.8 g29.6 g22.6 g342 kcal

Cheesy Low-Carb Tuna CasserolePin itFollow us 148.4k

Do you like this recipe? Share it with your friends! 

Dearna Bond
Creator of

Dearna Bond

Dearna is a passionate foodie and food photographer, and loves sharing her knowledge and enthusiasm for both via her food blog and online photography courses.

Let us know what you think, rate this recipe!

Leave a comment

Note: Any links to products or affiliate links will not be approved.
Please note that we do not offer personalised advice. For any diet related questions, please join our Facebook community.

Comments (7)

Love this recipe. Thank you for sharing.

I have the app but the cheesy low carb tuna casserole recipe on the blog I cannot add to my planner!!!!

Hi Pat, I'm sorry if there was a glitch - I seem to remember I fixed this (I always have to add a special code for that and I think I may have forgotten). It seems ok now, is it ok for you too? Just checking. Thank you!

Hi, I have just tried but still no add available at top right.
Take care, go well,
Pat Holland

I'm sorry about that Pat, I just checked and it works on two of my devices. Could you please send me a screenshot on Facebook (via DM) or at martina[at]ketodietapp[dot]com? Thank you!

Hello. I really want to make this. My younger sister bought me a 600ml double cream for the cheese sauce. This recipe only calls for 60mls. What do I do with the remaining cream? Especially as the cream has a very short shelf life. Would the cream last longer if I freeze it?
I've been going through this app for quick recipes that use double cream and I found chocolate truffles. But there'll still be loads of cream left!!

Hello Amina, you can freeze cream in an ice tray or in a freezer-friendly container.
Or you could make keto coffee creamer and condensed milk: Low-Carb & Keto Coffee Creamer Five Ways, or ice cream: Ice Creams
Truffles are an option too 😊