Keto Tuna Casserole Recipe brings a fresh, low-carb spin to a classic comfort dish that’s rich, creamy, and surprisingly simple to make. I love pulling this out on cooler evenings when I want something cozy and filling that won’t knock me out of ketosis. Whether you’re preparing a quick weeknight dinner or feeding family and friends who appreciate wholesome meals, this casserole hits all the marks — creamy, cheesy, and just the right amount of cozy with tuna and cauliflower rice blending perfectly together.
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What Makes This So Good
This Keto Tuna Casserole Recipe is more than just a low-carb meal—it’s a satisfying experience that balances creamy textures with a bit of crispiness, showcasing tuna in a way that’s both familiar and refreshing. It’s the perfect dish when you want something homemade that doesn’t mean hours in the kitchen but still delivers on comfort and nourishment.
- Big Flavor, Minimal Fuss: Combining savory tuna with sharp cheddar and aromatic garlic creates layers of flavor without complicated steps.
- Family-Friendly: Even my picky eaters enjoy this casserole — it’s mild but satisfying, with just the right creamy, cheesy appeal.
- Simple Ingredients: You probably already have everything on hand, from canned tuna to cauliflower rice and cheese, making prep a breeze.
- Works Any Night: Whether it’s a quick lunch, a cozy dinner, or leftovers on hand, this is a versatile recipe that fits your schedule.
Ingredient Guide
Choosing the right ingredients really sets this Keto Tuna Casserole Recipe apart. I’ll walk you through my favorite picks and little swaps to make sure your dish comes out as delicious and keto-friendly as possible.
- Tuna: Opt for good-quality canned tuna packed in water or olive oil. Draining well helps avoid extra moisture that can make the casserole soggy.
- Cauliflower Rice: Fresh or frozen works fine, but I love frozen for convenience. Just make sure to thaw and pat dry any excess water before mixing.
- Heavy Cream: This is key for richness and creaminess in the sauce—don’t substitute with milk, which thins the consistency.
- Cheddar Cheese: Sharp cheddar adds a lovely tang and melts beautifully. Feel free to mix in mozzarella for extra stretchiness if you like.
- Frozen Peas (Optional): Adds a touch of sweetness and color but can be skipped to reduce carbs further.
- Onion and Garlic: These aromatics elevate the flavor, but if you’re nightshade sensitive, you can use garlic-infused oil instead.
- Olive Oil: Use a good quality extra virgin for sautéing — it brings subtle fruitiness that pairs well with the savory casserole.
Quick Reminder: Full measurements are in the recipe card below.
How to Make Keto Tuna Casserole Recipe
Step 1 — Prep & Ready
Start by preheating your oven to 350°F (175°C). Meanwhile, finely dice your onion and mince the garlic cloves — these small chops help release their wonderful aroma into the casserole. If you’re using frozen cauliflower rice, thaw it just enough to drain any water so you don’t end up with a watery bake. Having everything ready before you start cooking helps the process flow smoothly and ensures your casserole comes out perfectly balanced.
Step 2 — Cook with Confidence
Heat a splash of olive oil in a skillet over medium heat and toss in your diced onion and garlic. Cook for 3-4 minutes until they soften and release that cozy, sweet aroma you’ll instantly love. Then in a bowl, mix together the drained tuna, cauliflower rice, heavy cream, peas if using, plus salt and pepper to taste. Stir in half the cheddar cheese now — this helps it melt evenly throughout. Pour the whole mixture into a greased 9×9-inch baking dish, then sprinkle the remaining cheddar on top for that bubbly, golden finish.
Step 3 — Finish & Serve
Bake your casserole for 25 to 30 minutes until the cheese is melted, bubbly, and just starting to develop those crispy edges—the hallmark of a well-made casserole. Let it stand for at least 5 minutes before diving in; this rest time thickens the sauce and makes serving easier. You’ll notice a wonderful blend of savory tuna and creamy sauce with just the right hint of cheddar richness. Trust me, the first warm forkful will convince you this is a new keto favorite.
Extra Helpful Tips
I often find that keeping an eye on moisture content is key for the best texture—too much water from thawed cauliflower rice or undrained tuna can turn the casserole mushy, which nobody wants! Also, if you’re prepping ahead, you can assemble the casserole and refrigerate it unbaked for up to 24 hours. This is a lifesaver when you want dinner ready to pop in the oven after a busy day.
- Watch for This Sign: When the cheese topping turns bubbly and golden brown, your casserole is ready to come out.
- Temperature Trick: Let the casserole cool on the counter for a few minutes before serving—it thickens perfectly without drying out.
- Prep-Ahead Option: Assemble your casserole in advance but hold off on baking until right before dinner.
- Avoid This Common Mistake: Don’t forget to drain the tuna well and squeeze excess moisture from the cauliflower rice to prevent sogginess.
Serve & Enjoy
Easy Enhancements
You can boost this Keto Tuna Casserole Recipe with fresh herbs like chopped parsley or dill, which add brightness against the creamy base. Fancy a bit more texture? Toasted almond slivers or pork rind crumbs sprinkled on top right before serving give an addictively crunchy contrast. For a touch of heat, a little smoked paprika or red pepper flakes works wonders without overwhelming the flavors.
Tasty Pairings
This casserole pairs perfectly with a crisp green salad dressed lightly in lemon vinaigrette to cut through the richness. For beverages, a dry white wine or sparkling water with a splash of lime refreshes the palate nicely. If you want extra veggies on the side, steamed asparagus or roasted Brussels sprouts are fantastic low-carb choices.
Quick Plating Tips
Spoon the casserole into warm bowls or plates for instant cozy vibes. A sprinkle of freshly grated parmesan over the top adds sparkle and aroma. If you’ve got fresh herbs on hand, garnish with a sprig of parsley or dill for a pop of color that makes your dish look as good as it tastes.
Store, Freeze & Reheat
Fridge Storage
You can store leftovers in an airtight container for up to 3 days. You’ll notice the texture firms up a bit in the fridge, which actually makes it easier to reheat without losing cohesion. Just be sure to keep it sealed to avoid drying out or flavor loss.
Freezer Friendly?
This Keto Tuna Casserole Recipe freezes well if carefully stored in a freezer-safe container. To avoid sogginess, cool it completely before freezing. When ready to eat, thaw overnight in the fridge rather than microwaving straight from frozen for best texture retention.
Reheat Like New
Reheat gently in a preheated 325°F oven covered with foil to keep moisture, about 15–20 minutes until warmed through. If in a hurry, microwave in short bursts at medium power, stirring in between, to keep the creamy texture intact without drying out. A quick sear in a hot skillet is also a cozy option that refreshes crisp edges beautifully.
Keto Tuna Casserole Recipe FAQs
You can, but canned tuna offers convenience and consistent flavor. If using fresh tuna, cook it first and flake it before mixing to maintain the casserole's texture and taste.
No, peas are optional and add a touch of sweetness and color. If you prefer to keep carbs as low as possible, feel free to omit them without losing the dish’s deliciousness.
Absolutely! Finely chopped zucchini or even riced broccoli can be great alternatives, though keep moisture levels in check to prevent sogginess.
Stick to cauliflower rice, skip the peas, and use full-fat dairy ingredients. Also, consider topping with pork rind crumbs instead of breadcrumbs for added crunch without carbs.
Final Flavor Thoughts
If you try this Keto Tuna Casserole Recipe, I’d love to hear how it turns out! Maybe rate it or share your own twists — like adding sautéed mushrooms or swapping herbs. Cooking should be fun and adaptive, and this recipe is such a comforting base to make your own. Happy cooking and enjoy every creamy, cheesy bite!
Print📖 Recipe
Keto Tuna Casserole Recipe
This Keto Tuna Casserole is a delicious low-carb twist on the classic comfort dish. Packed with protein-rich tuna, creamy heavy cream, and cheesy goodness, it uses cauliflower rice to keep it keto-friendly while still providing a satisfying, hearty meal. Perfect for those following a ketogenic diet or anyone looking for a tasty, gluten-free casserole.
- Prep Time: 10 minutes
- Cook Time: 30 minutes
- Total Time: 40 minutes
- Yield: 4 servings
- Category: Main Dish
- Method: Baking
- Cuisine: American
- Diet: Low Carb
Ingredients
Seafood and Vegetables
- 2 cans (5 oz each) tuna, drained
- 1 cup cauliflower rice (fresh or frozen)
- ½ cup frozen peas (optional)
- ¼ cup diced onion
- 2 cloves garlic, minced
Dairy and Seasonings
- 1 cup heavy cream
- 1 cup shredded cheddar cheese
- Salt and pepper to taste
Others
- Olive oil for cooking
Instructions
- Preheat Oven: Preheat your oven to 350°F (175°C) to prepare for baking the casserole later.
- Sauté Aromatics: In a skillet, heat olive oil over medium heat. Add the diced onion and minced garlic, cooking until they are softened and fragrant, about 3-5 minutes.
- Mix Ingredients: In a mixing bowl, combine the drained tuna, cauliflower rice, heavy cream, frozen peas (if using), salt, and pepper. Stir in half of the shredded cheddar cheese to create a creamy, flavorful mixture.
- Assemble Casserole: Pour the tuna mixture into a greased 9×9-inch baking dish, spreading evenly. Top with the remaining cheddar cheese for a golden, cheesy crust.
- Bake: Bake in the preheated oven for 25-30 minutes until the cheese is melted, bubbly, and lightly browned on top.
- Serve: Remove from oven and let cool slightly before serving to allow the casserole to set and flavors to meld.
Notes
- The frozen peas are optional and can be omitted to reduce carbs further.
- Cauliflower rice can be fresh or frozen depending on convenience.
- You can substitute cheddar cheese with other keto-friendly cheeses like mozzarella or Monterey Jack.
- For added flavor, consider sprinkling some paprika or dried herbs before baking.
- Leftovers store well in the refrigerator for up to 3 days and can be reheated in the oven or microwave.
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