I made a lazy one-pot Keto Tuna Noodle Casserole that swaps traditional noodles for low-carb ingredients and leans on pantry staples to deliver a quick, no-fuss dinner.

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I love a lazy satisfying dinner so I made a one pot keto tuna casserole that feels like a treat without the fuss. It stars solid white tuna in water layered over frozen riced cauliflower, then finishes up silky and comforting.

I stole ideas from Keto Tuna Noodle Casserole but stripped away the carbs and drama, making something faster and kinda messy in the best way. It sits right in my Keto Cast Iron Skillet Recipes Dinner lineup and honestly it disappears before I can even plate it.

If you like low carb casseroles this might surprise you.

Ingredients

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Riced cauliflower: low carb, good fiber, soaks up sauce keeps casserole light
Tuna: high protein lean salty, adds seafood flavor and texture, quick
Cream cheese: rich fat, super creamy, makes sauce silky but also heavy
Heavy cream: more fat helps thicken sauce gives indulgent mouthfeel, use sparingly
Cheddar: sharp melty flavor adds protein and savory depth, very satisfying
Parmesan: salty umami boost, great for topping and extra cheesy punch
Onion: adds sweetness and aromatic base when cooked, balances all the richness
Garlic: pungent bite a little goes far lifts the whole dish dont overdo
Pork rinds: crunchy keto topping option, high fat and sodium, super crispy
Lemon and Dijon: bright acid from lemon Dijon gives tang and balances richness

Ingredient Quantities

12 oz frozen riced cauliflower

2 (5 oz) cans solid white tuna in water

4 oz cream cheese full fat

1/2 cup heavy cream

1/4 cup mayonnaise (full fat)

1 to 1 1/2 cups shredded sharp cheddar cheese

1/4 cup grated Parmesan cheese

1 small yellow onion about 4 oz

2 cloves garlic

2 tbsp butter or olive oil

1 tsp Dijon mustard

1 tbsp lemon juice

1/2 tsp smoked paprika or regular paprika

Salt and black pepper

1/2 cup crushed pork rinds for topping (optional)

1/4 cup chopped fresh parsley for garnish (optional)

How to Make this

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1. Prep everything first: dice the small yellow onion, mince the garlic, drain and flake the tuna, measure cheeses and the other liquids. Loosen the frozen riced cauliflower by microwaving it 1 to 2 minutes or let it sit 5 minutes, then pat it dry with paper towels to avoid a watery casserole.

2. Heat 2 tbsp butter or olive oil in a large oven-safe skillet or Dutch oven over medium heat. Add the onion and cook until soft and translucent, about 4 to 5 minutes.

3. Add the minced garlic and cook 30 to 45 seconds until fragrant, don’t let it burn.

4. Turn the heat to low and add the 4 oz cream cheese, 1/2 cup heavy cream, 1/4 cup mayonnaise, 1 tsp Dijon mustard, 1 tbsp lemon juice and 1/2 tsp smoked or regular paprika. Stir constantly until the cream cheese melts and you have a smooth, creamy sauce. Season with salt and black pepper to taste.

5. Stir in the drained tuna, breaking it up with your spoon or fork so it distributes evenly in the sauce.

6. Add the riced cauliflower to the pan, stir to combine, then increase heat to a gentle simmer. Cover and cook 5 to 7 minutes, stirring once or twice, until the cauliflower is tender and much of the excess moisture has cooked off.

7. Reduce heat to low and stir in 1 to 1 1/2 cups shredded sharp cheddar and 1/4 cup grated Parmesan until melted and the casserole is creamy. Taste and adjust salt and pepper, more lemon if you want a brighter flavor.

8. If you want a crunchy topping, sprinkle 1/2 cup crushed pork rinds evenly over the top. For a browned top, place the skillet under a hot broiler 1 to 3 minutes until golden and bubbly, watching closely so it doesn’t burn. If you don’t use a broiler, you can brown pork rinds separately in a small pan and sprinkle them on.

9. Let the casserole rest 2 minutes to thicken slightly, then garnish with 1/4 cup chopped fresh parsley if using.

10. Serve hot straight from the pan. Leftovers keep well in the fridge for 3 to 4 days and reheat nicely in a skillet or microwave.

Equipment Needed

1. Large oven-safe skillet or Dutch oven, big enough for the whole casserole and to finish under the broiler
2. Cutting board and chef’s knife, for dicing the onion and mincing the garlic
3. Measuring cups and spoons, for the cream, mayo, lemon, mustard and spices
4. Can opener and fork, to drain and flake the tuna
5. Rubber spatula or wooden spoon, for stirring and scraping the sauce
6. Fine mesh sieve or colander plus paper towels, to drain and pat the riced cauliflower dry
7. Cheese grater, for shredding cheddar and grating Parmesan (or use pre-shredded)
8. Oven mitts and a small baking sheet or broiler-safe rack, for browning the topping and safe handling

FAQ

How many people does this serve?

About 3 to 4 normal portions, maybe 2 big eaters. You get most of the calories from the cheese and tuna so portions feel pretty filling.

Can I use fresh cauliflower instead of frozen riced cauliflower?

Yes. Pulse florets in a food processor until rice sized, then cook a few minutes longer to drive off extra water. Squeeze it in a towel or fine mesh to remove moisture before adding to the pan, or the casserole can get soggy.

Do I have to use pork rinds for the topping?

Nope, they are optional. For a crunch you can use crushed Parmesan crisp, toasted almond slivers, or just extra cheddar melted on top. If you want it lighter skip the crunchy topping altogether.

How do I keep the casserole creamy and not watery?

Drain the tuna very well, thaw and press out excess water from the frozen cauliflower, cook off liquid from the onion, and melt the cream cheese slowly so it emulsifies with the heavy cream. Add the shredded cheddar late, off high heat, so the sauce stays smooth.

Can I make this ahead, and how do I reheat it?

Yes make ahead, store in an airtight container in the fridge for 3 to 4 days. Reheat in the oven at 350 F until warm for best texture, or microwave for a quick fix. If it seems a bit dry add a splash of heavy cream when reheating.

Any easy swaps if I dont want cheese or need a dairy free version?

For dairy free try full fat coconut cream instead of heavy cream and a dairy free cream cheese substitute, but texture will change and flavor will be different. You can also swap tuna for canned salmon or shredded rotisserie chicken if you want variety.

ONE POT KETO TUNA CASSEROLE Recipe Substitutions and Variations

Riced cauliflower: swap 1:1 with frozen broccoli rice for a bit more bite, or use 10–12 oz shredded zucchini (squeeze out the water first) for a softer, milder base.
Tuna: use canned salmon (drained) 1:1 for a richer flavor, or swap for about 2 cups shredded rotisserie chicken if you want milder taste and less fishiness.
Cream cheese (4 oz): replace 1:1 with mascarpone for an even creamier texture, or use full fat ricotta 1:1 but drain well so the casserole doesn’t get watery.
Pork rind topping (optional): use 1/2 cup toasted almond flour mixed with 1 tbsp melted butter for a crunchy low carb crust, or bake 1/2 cup grated Parmesan until golden and crumble for a salty crisp topping.

Pro Tips

– Dry that riced cauliflower like your life depends on it. Microwave or thaw it then wrap in a clean kitchen towel and squeeze hard, do it in batches if you need to. If you skip this youll end up with a soupy casserole and nobody wants that.

– Don’t skimp on draining and flaking the tuna, pat it really dry with paper towels. If the tuna tastes a little flat add a splash of lemon and a teaspoon of Dijon to brighten it up, or use oil packed tuna for a richer bite.

– For the creamiest sauce cut the cream cheese into small cubes and bring it close to room temp, melt it slowly over low heat and whisk the cream in slowly, then fold in the cheddar off the heat. Use freshly grated cheddar not the pre-shredded stuff, it melts way smoother.

– If you want crunch toast the pork rinds or nuts in a dry skillet first and sprinkle them on right before serving so they stay crisp. If you broil to brown the top watch it like a hawk, broilers go from perfect to burned real fast.

– Taste as you go and err on the side of under-salting since cheeses concentrate, then brighten with more lemon or a tiny splash of vinegar at the end if it feels dull. Leftovers reheat best gently in a skillet with a splash of cream or water to bring the sauce back to life, and store any crunchy topping separately.

ONE POT KETO TUNA CASSEROLE Recipe

Recipe by Sarah level

0.0 from 0 votes

I made a lazy one-pot Keto Tuna Noodle Casserole that swaps traditional noodles for low-carb ingredients and leans on pantry staples to deliver a quick, no-fuss dinner.

Servings

servings

Calories

810

kcal

Equipment: 1. Large oven-safe skillet or Dutch oven, big enough for the whole casserole and to finish under the broiler
2. Cutting board and chef’s knife, for dicing the onion and mincing the garlic
3. Measuring cups and spoons, for the cream, mayo, lemon, mustard and spices
4. Can opener and fork, to drain and flake the tuna
5. Rubber spatula or wooden spoon, for stirring and scraping the sauce
6. Fine mesh sieve or colander plus paper towels, to drain and pat the riced cauliflower dry
7. Cheese grater, for shredding cheddar and grating Parmesan (or use pre-shredded)
8. Oven mitts and a small baking sheet or broiler-safe rack, for browning the topping and safe handling

Ingredients

12 oz frozen riced cauliflower
2 (5 oz) cans solid white tuna in water
4 oz cream cheese full fat
1/2 cup heavy cream
1/4 cup mayonnaise (full fat)
1 to 1 1/2 cups shredded sharp cheddar cheese
1/4 cup grated Parmesan cheese
1 small yellow onion about 4 oz
2 cloves garlic
2 tbsp butter or olive oil
1 tsp Dijon mustard
1 tbsp lemon juice
1/2 tsp smoked paprika or regular paprika
Salt and black pepper
1/2 cup crushed pork rinds for topping (optional)
1/4 cup chopped fresh parsley for garnish (optional)

Directions

Prep everything first: dice the small yellow onion, mince the garlic, drain and flake the tuna, measure cheeses and the other liquids. Loosen the frozen riced cauliflower by microwaving it 1 to 2 minutes or let it sit 5 minutes, then pat it dry with paper towels to avoid a watery casserole.
Heat 2 tbsp butter or olive oil in a large oven-safe skillet or Dutch oven over medium heat. Add the onion and cook until soft and translucent, about 4 to 5 minutes.
Add the minced garlic and cook 30 to 45 seconds until fragrant, don't let it burn.
Turn the heat to low and add the 4 oz cream cheese, 1/2 cup heavy cream, 1/4 cup mayonnaise, 1 tsp Dijon mustard, 1 tbsp lemon juice and 1/2 tsp smoked or regular paprika. Stir constantly until the cream cheese melts and you have a smooth, creamy sauce. Season with salt and black pepper to taste.
Stir in the drained tuna, breaking it up with your spoon or fork so it distributes evenly in the sauce.
Add the riced cauliflower to the pan, stir to combine, then increase heat to a gentle simmer. Cover and cook 5 to 7 minutes, stirring once or twice, until the cauliflower is tender and much of the excess moisture has cooked off.
Reduce heat to low and stir in 1 to 1 1/2 cups shredded sharp cheddar and 1/4 cup grated Parmesan until melted and the casserole is creamy. Taste and adjust salt and pepper, more lemon if you want a brighter flavor.
If you want a crunchy topping, sprinkle 1/2 cup crushed pork rinds evenly over the top. For a browned top, place the skillet under a hot broiler 1 to 3 minutes until golden and bubbly, watching closely so it doesn't burn. If you don't use a broiler, you can brown pork rinds separately in a small pan and sprinkle them on.
Let the casserole rest 2 minutes to thicken slightly, then garnish with 1/4 cup chopped fresh parsley if using.
Serve hot straight from the pan. Leftovers keep well in the fridge for 3 to 4 days and reheat nicely in a skillet or microwave.

Notes

Below you’ll find my best estimate of this recipe’s nutrition facts. Treat the numbers as a guide rather than a rule—great food should nourish both body and spirit. Figures are approximate, and the website owner assumes no liability for any inaccuracies in this recipe.