When You Need a Cozy Low Carb Cheesy Tuna Casserole Tonight

There’s something about a bubbling casserole fresh from the oven that instantly makes a kitchen feel like home. This low carb cheesy tuna casserole hits that note beautifully—creamy, cheesy, and packed with protein without any heavy carbs weighing you down. It’s the kind of dish you might find yourself craving on a chilly evening when you want something satisfying but not too complicated.

I remember the first time I made this. I was distracted halfway through chopping the cauliflower because the neighbor’s dog started barking, and I wasn’t even sure if I had added enough spices. But once it came out golden and bubbly, all those little kitchen hiccups melted away. The sharp cheddar and mozzarella melted together in that perfect way, while the tuna kept it hearty. And the cauliflower? You’d almost forget it wasn’t pasta. It’s the kind of comfort food that feels indulgent but doesn’t leave you sluggish afterward.

• It’s creamy and cheesy without relying on carbs, so you can enjoy comfort food without the guilt.
• Quick to prep and bake, making it perfect for busy weeknights when you want something homemade but easy.
• The flavors balance out nicely—the sharpness of cheddar, the creaminess from sour cream and mayo, and a subtle smoky paprika kick.
• It’s simple—and that’s kind of the point. No need for fancy ingredients or complicated steps.
• Leftovers reheat well, but honestly, it rarely lasts long enough to worry about storing.

If you’re wondering whether it’s worth it to try a low-carb tuna casserole, give this one a shot. It’s a little different from traditional casseroles but still hits all the cozy notes.

Low Carb Cheesy Tuna Casserole

Print Recipe

A delicious and comforting low carb cheesy tuna casserole that’s perfect for a quick and healthy dinner. Packed with protein and creamy cheese, this casserole is both satisfying and easy to make.

• Prep Time: 10 minutes
• Cook Time: 25 minutes
• Total Time: 35 minutes
• Yield: 4

Ingredients

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2 tablespoons olive oil
1 small yellow onion, finely chopped
2 cloves garlic, minced
12 ounces cauliflower florets, chopped into small pieces
1 cup shredded sharp cheddar cheese
1/2 cup shredded mozzarella cheese
1/2 cup grated Parmesan cheese
1/2 cup sour cream
1/2 cup mayonnaise
1/2 cup heavy cream
2 cans (5 ounces each) tuna in water, drained
1 teaspoon Dijon mustard
1/2 teaspoon salt
1/4 teaspoon black pepper
1/4 teaspoon smoked paprika
1/4 cup chopped fresh parsley

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Instructions

Preheat the oven to 375°F (190°C).
Heat olive oil in a large skillet over medium heat. Add the chopped onion and cook for 3-4 minutes until softened.
Add the minced garlic to the skillet and cook for another 1 minute until fragrant.
Add the chopped cauliflower florets to the skillet and cook for 5-7 minutes until tender but still slightly firm. Remove from heat.
In a large mixing bowl, combine the sour cream, mayonnaise, heavy cream, Dijon mustard, salt, black pepper, and smoked paprika. Mix well.
Add the cooked cauliflower mixture to the bowl along with the drained tuna, shredded cheddar cheese, shredded mozzarella cheese, grated Parmesan cheese, and chopped parsley. Stir until all ingredients are evenly combined.
Transfer the mixture into a greased 8×8 inch baking dish and spread evenly.
Bake in the preheated oven for 20-25 minutes until the casserole is bubbly and the cheese on top is melted and golden.
Remove from the oven and let cool for 5 minutes before serving.

Don’t worry about having special equipment to pull this off; a simple skillet and baking dish do the trick. I’ve also found that swapping out the cauliflower for broccoli can work if you want a slightly different texture—though I haven’t tested it extensively. Sometimes I toss in a handful of chopped bell peppers for extra color and crunch, but that’s just me riffing. For serving, a crisp green salad or steamed asparagus rounds out the meal nicely.

FAQ

Can I use canned tuna in oil instead of water? Sure, but you might want to drain it well to avoid extra grease.

Is this dish freezer-friendly? I haven’t tried freezing it, but since it has dairy, it might change texture a bit after thawing.

Can I make this dairy-free? You’d have to experiment with substitutes for the cheese and cream—maybe a vegan cheese alternative, but I haven’t tested that.

How spicy is it? The smoked paprika adds a mild warmth, nothing overpowering.

Ready to cozy up with a dish that feels like a warm hug? This low carb cheesy tuna casserole is waiting for you to give it a try.