ONE POT KETO TUNA CASSEROLE Recipe

I just whipped up a Keto Tuna Noodle Casserole that somehow turns plain pantry cans into a ridiculously creamy, low-carb dinner you’ll want on repeat.

I’m obsessed with this one pot keto tuna casserole. I love that it’s sloppy in the best way, all creamy from cream cheese and melted shredded sharp cheddar cheese, and actually makes me feel like I ate something worth writing home about.

It hits that weird sweet spot between lazy and worthy, like a classic Keto Tuna Noodle Casserole but without the carbs and without drama. I make it on nights when I need serious Low Carb Dinner Recipes that don’t act like punishment.

It’s rich, salty, a little sharp, and exactly what I want for dinner every single time.

Ingredients

• Cauliflower: Light, low-carb bite that soaks up creaminess and gives some veggie crunch.
• Tuna: Big protein hit, flaky and salty, keeps this casserole honest and filling.
• Cream cheese: Basically the glue that makes everything smooth and slightly tangy.
• Heavy cream: Rich mouthfeel, makes the sauce decadent without tasting heavy.
• Sour cream: Adds tang and creaminess, it’s what keeps it from tasting flat.
• Cheddar: Sharp, melty goo that adds bold cheesy comfort and a golden top.
• Parmesan: Nutty, salty finish that cuts through the cream and adds depth.
• Onion: Sweet background flavor, gives a little bite and savory balance.
• Garlic: Small punch of warmth and aroma, you’ll smell it first.
• Butter or oil: Helps cook aromatics and adds a silky, rich base.
• Chicken broth: Keeps things saucy and savory without watering everything down.
• Kosher salt: Brings out all the flavors, don’t skip tasting as you go.
• Black pepper: Simple heat and earthiness that ties the whole dish together.
• Parsley: Fresh green notes, brightens each spoonful and cuts richness.
• Xanthan gum: Optional thickener, it’s handy if you want a firmer sauce.

Ingredient Quantities

• 1 medium head cauliflower, cut into florets, about 4 cups (500g)
• 12 ounces canned tuna, drained (about 2 large cans)
• 4 ounces cream cheese, softened
• 1/2 cup heavy cream
• 1/2 cup sour cream
• 1 1/2 cups shredded sharp cheddar cheese, divided
• 1/4 cup grated Parmesan cheese
• 1 small yellow onion, finely diced
• 2 cloves garlic, minced
• 2 tablespoons butter or olive oil
• 1/2 cup low sodium chicken broth
• 1 teaspoon kosher salt, or to taste
• 1/2 teaspoon ground black pepper
• 1/2 teaspoon dried parsley or 2 tablespoons fresh chopped parsley
• 1/2 teaspoon xanthan gum, optional for extra thickening

How to Make this

1. Heat a large ovenproof skillet or pot over medium heat and add 2 tablespoons butter or olive oil. Add the finely diced onion and cook until soft and translucent, about 4 minutes, then stir in the minced garlic and cook 30 seconds more.

2. Add the cauliflower florets to the pot, pour in 1/2 cup low sodium chicken broth, season with 1 teaspoon kosher salt and 1/2 teaspoon black pepper, cover and let simmer until cauliflower is fork tender, about 8 to 10 minutes.

3. While the cauliflower cooks, drain the tuna well and soften the 4 ounces cream cheese (microwave 10 to 15 seconds if needed). Grate the cheddar if not pre-shredded and measure the Parmesan.

4. Uncover the pot and stir in the softened cream cheese, 1/2 cup heavy cream and 1/2 cup sour cream until smooth. If using, sprinkle in 1/2 teaspoon xanthan gum now and whisk quickly to prevent clumps; it will help thicken the sauce.

5. Add 1 cup of the shredded sharp cheddar and the 1/4 cup grated Parmesan, stirring until the cheeses melt into a creamy sauce. If the sauce seems too thin, simmer 2 to 3 minutes to reduce, tasting and adjusting salt and pepper.

6. Gently fold in the drained tuna and 1/2 teaspoon dried parsley or 2 tablespoons fresh chopped parsley, breaking the tuna into bite sized pieces but not mashing it completely. Cook 1 to 2 minutes to heat the tuna through.

7. Taste for seasoning and adjust with more salt or pepper if needed. If you want a thicker casserole, simmer a little longer uncovered or add a tiny pinch more xanthan gum mixed into a tablespoon of cold water before whisking in.

8. Sprinkle the remaining 1/2 cup shredded cheddar evenly over the top. If you want a browned crust, place the skillet under a hot broiler for 2 to 4 minutes, watching closely until the cheese bubbles and gets golden. If you dont broil, just let the cheese melt on the stovetop.

9. Remove from heat and let rest 3 to 5 minutes so the sauce sets a bit, then garnish with extra chopped parsley if you used fresh.

10. Serve hot straight from the pot with a simple green salad or steamed greens for extra veggies. Leftovers keep well covered in the fridge for 3 to 4 days.

Equipment Needed

1. Large ovenproof skillet or heavy pot with lid
2. Cutting board and sharp chef knife (for cauliflower, onion, parsley)
3. Can opener and fine mesh strainer or colander (to drain tuna)
4. Measuring cups and spoons
5. Wooden spoon or heatproof spatula for stirring
6. Whisk (for smoothing in cream cheese and xanthan gum)
7. Cheese grater (for cheddar and Parmesan)
8. Small mixing bowl and rubber spatula (to soften/mix cream cheese)
9. Oven mitts or potholders and a baking sheet if you broil the top

FAQ

ONE POT KETO TUNA CASSEROLE Recipe Substitutions and Variations

• Cauliflower: swap with chopped broccoli florets or thinly sliced zucchini for a lower-carb, similar-texture option. Broccoli will hold up more, zucchini gets softer so drain well.
• Tuna: canned salmon or shredded rotisserie chicken both work great. Salmon adds richness, chicken gives a milder flavor and stretches the dish farther.
• Cream cheese / heavy cream / sour cream mix: replace with full fat Greek yogurt plus a splash of heavy cream to loosen if needed. Greek yogurt gives tang and cuts calories, but heat gently so it doesn’t break.
• Xanthan gum (thickener): use 1 tablespoon psyllium husk powder or 2 tablespoons almond flour to thicken instead. Psyllium sets firmer, almond flour gives a slightly grainier texture but keeps it keto friendly.

Pro Tips

1) Drain the tuna super well and press it gently between paper towels before folding in. Too much moisture will water down the sauce and make the casserole runny, especially if you skip the xanthan gum.

2) Use a mix of fresh and pre-shredded cheeses if you can. Freshly shredded melts smoother, but a little pre-shredded helps keep the topping from getting greasy. If the sauce looks thin, remove the lid and simmer 2 to 3 minutes to reduce, don’t just keep dumping more cheese.

3) Cook the cauliflower until just fork tender, not falling apart. Overcooked florets turn mushy and make the texture go flat. If you like a bit more bite, cut some florets a touch larger so you get contrast.

4) If you want a quicker, creamier finish, warm the cream cheese and heavy cream together before adding to the pot so they blend instantly. And if you add xanthan gum, whisk it into a tablespoon of cold water first so it distributes evenly and you avoid clumps.