This Creamy Fish Casserole is the cozy, family-friendly dish you’ll want on repeat! With tender flakes of cod, layers of soft potatoes, and a golden cheesy top, it’s hearty, comforting, and simple enough for a weeknight. As an allergy mom, I know how important it is to have recipes that feel both special and safe, and this one checks all the boxes. Easy to make, big on flavor, and always a crowd-pleaser—this casserole is proof that simple ingredients can make the most satisfying meals.
Oriana’s Thoughts On The Recipe
When I first started creating egg-free recipes, I worried that comforting dishes like casseroles would lose their magic. But this Creamy Fish Casserole quickly became a staple in our home—because it’s warm, filling, and brings everyone to the table with a smile. My kids love the cheesy crust, and I love how easy it is to pull together with pantry staples.
As a mom managing food allergies, I test and retest every recipe until it’s foolproof. This casserole is one of those dishes you can trust for both busy weeknights and special family dinners. It’s safe, simple, and oh-so comforting—just the way homemade food should be.
Why You’ll Want to Try My Recipe
Ingredients You’ll Need, Substitutions & Notes
Please check the recipe card at the bottom of the post for exact quantities and detailed instructions (scroll down).
- Cheese: You can use any cheese you like. I used 5 Cheese Italian Slices (about 200 g) and Parmesan Cheese. I suggest using a melty cheese, such as cheddar, mozzarella, Gouda, Monterey Jack, Fontina, or Swiss.
- Fish: You can use any fish you prefer, but white fish like cod, haddock, or tilapia are popular choices due to their mild flavor that pairs well with creamy sauces. I personally like to use skinless, boneless Alaska Cod fillets, wild-caught. Fresh or frozen cod fillets can be found in most fish markets—frozen cod fillets are available in most grocery stores, such as Walmart or Target.
- Potatoes: The best to use are Russet or Yukon potatoes. Slice the potatoes into about ⅛-inch (3 mm) thick slices.
- Butter: I like to use unsalted butter, but if salted butter is what you have handy, you can use it; make sure to reduce the salt a bit.
- Heavy cream
- Half and half
- Onion Powder & Garlic Powder: For flavor!
- Salt & Black pepper: To season.
- Parsley (To garnish; this is optional).
Food Allergy Swaps
- Dairy-Free: To make this recipe dairy-free, you can easily swap out the dairy ingredients for non-dairy alternatives. Cheese: Use your favorite dairy-free melty-style cheese. I like 365 By Whole Foods Market, Cheese Non-Dairy Gouda Slices or MIYOKO’S Fresh Vegan Mozzarella, Organic Classic Plant Milk Cheese. Butter: Use vegan butter instead of dairy butter. Many brands are available in stores. I usually use Earth Balance Vegan Buttery Sticks or Miyoko’s Creamery Organic Vegan Butter. Heavy Cream: You can use a non-dairy cream, such as Silk, Country Crock Plant Cream, or Califia Farms.
Overview: How to Make Cheesy Potatoes and Cod Casserole Step By Step
Please check the recipe card at the bottom of the post for exact quantities and detailed instructions (scroll down).
- Season the Fish
Season the fish fillets with salt and pepper. Set aside
- Make the Cream Sauce
Combine all ingredients of the sauce in a microwave-safe cup or bowl. Place the cup in the microwave and heat until the butter is melted and the mixture is warm, in about three 30-second bursts. Set aside.u003cbru003eu003cbru003eu003cimg class=u0022wp-image-20731u0022 style=u0022width: 900px;u0022 src=u0022https://mommyshomecooking.com/wp-content/uploads/2018/11/Cheesy-Potatoes-and-Cod-Casserole-7.jpgu0022 alt=u0022Cheesy Potatoes and Cod Casserole | Mommy’s Home Cookingu0022u003e
- Assemble the Casserole
Add 1/3 of the cream mixture to the bottom of the casserole dish. Spread about 1/3 of the potato slices on top of the cream. Arrange half of the fish fillets on top of the cream, and then top the fish with cheese. Repeat one more time, finishing with one more layer of potatoes and the remaining cream mixture.u003cbr/u003eu003cbr/u003eu003cimg class=u0022wp-image-20730u0022 style=u0022width: 900px;u0022 src=u0022https://mommyshomecooking.com/wp-content/uploads/2018/11/Cheesy-Potatoes-and-Cod-Casserole-6.jpgu0022 alt=u0022Cheesy Potatoes and Cod Casserole | Mommy’s Home Cookingu0022/u003e
- Bake
Cover loosely with foil and bake for 45 – 60 minutes, or until the potatoes are fork-tender. Remove from oven, sprinkle with Parmesan cheese, and bake without foil for 10 minutes or until golden. Let it rest for 5 minutes before serving. Garnish with chopped parsley, if desired. Serve hot.
Recipe Tips
Fish. I recommend using Alaska Cod Skinless Boneless Fillets. Cod fillets can be found in most fish markets. I usually buy it at my local Asian store, which sells tons of fresh fish. You can also find frozen cod fillets in most grocery stores. If you’re using frozen fish in this creamy fish casserole, I recommend thawing the fish before baking. Thawing the fish ensures that it cooks evenly and thoroughly throughout the casserole.
Potatoes. The best to use are Russet or Yukon potatoes. Slice the potatoes into about ⅛-inch (3 mm) thick slices. I like to use my mandoline to slice the potatoes.
Warm up the Cream Mixture. I like to warm the cream mixture in the microwave before putting the dish in the oven because it reduces the chance that the mixture curdles.
Pat the cod completely dry with paper towels before you layer it in. Fish releases moisture as it bakes, and if you skip this step, that extra liquid thins out your cream sauce and leaves you with a soupy casserole instead of a creamy one. It takes ten extra seconds and makes a real difference.”
The cream mixture will look thin and loose when you pour it in — that’s normal. It thickens as it bakes, thanks to the starch the potatoes release. Resist the urge to add extra cornstarch or flour. If it still looks a touch loose right out of the oven, let the casserole rest the full 5 minutes before serving; it firms right up as it sits.
What to Serve With
This casserole is rich, so I like to balance it with something bright. Try Perfect Air Fryer Asparagus for a quick green side that doesn’t compete with the cream sauce, or a simple Roasted Tomato Caprese Salad for something fresh and acidic to cut through the richness. And if you want something to mop up every bit of that sauce, my Soft & Easy Eggless Dinner Rolls are made for exactly this.
Frequently Asked Questions
Technically, you can. However, keep in mind that freezing and reheating can affect the texture of some ingredients, such as the cream sauce. The sauce might separate slightly upon thawing and reheating.
You can use any fish you prefer, but white fish like cod, haddock, or tilapia are popular choices due to their mild flavor that pairs well with creamy sauces.
Yes, but thaw it first — overnight in the fridge, or the cold-water method (sealed bag, water changed every 30 minutes) until it’s fully thawed. Then pat it very dry before layering. Baking straight from frozen adds extra moisture to the dish and is one of the fastest ways to end up with a watery casserole.
Two usual culprits: the fish wasn’t patted dry before it went in, or the foil came off too early. Keep it covered for the full bake time so the potatoes cook through and the sauce has time to thicken, and only uncover for the last 10 minutes to brown the top.
Recipe Card
Creamy Fish Casserole
Important
• For best results, I highly recommend using a kitchen scale to measure the ingredients.
Ingredients
- 4 – 5 (about 600- 750 g) skinless, boneless cod fillets – You can also use haddock or tilapia (see notes)
- Salt & black pepper, to taste
- 1 tablespoon (14 g) unsalted butter
- 3 lb (1.4 kg) potatoes, peeled and thinly sliced (about 6-8 medium potatoes) (see notes)
- 2 cups (226 g) of your favorite melty cheese, sliced or shredded (see notes)
- 1 cup (113 g) shredded Parmesan cheese
- Parsley, chopped (to garnish – optional)
Cream Sauce:
- 6 tablespoons (85 g) unsalted butter
- 2 cups (480 ml) heavy cream
- 1 cup (240 ml) half and half
- 2 teaspoons onion powder
- 2 teaspoons garlic powder
- ½ teaspoon black pepper
- 2 teaspoons kosher salt
Instructions
Season The Fish:
- Season the fish fillets with salt and pepper. Set aside
Preheat the Oven and Prepare the Baking Dish:
- Preheat the oven to 400º F (200°C). Butter a baking dish with 1 tablespoon of butter. I used an oval casserole baking dish (1.5 Qt.).
Prepare the Creamy Sauce:
- Combine all ingredients of the cream sauce in a microwave-safe cup or bowl. Place the cup in the microwave and heat until the butter is melted and the mixture is warm, about 2 – 3, 30-second bursts. Set aside.
Assemble:
- Add 1/3 of the cream mixture to the bottom of the baking dish. Spread about 1/3 of the potato slices on top of the cream. Add half of the fish fillets, then top the fish with 1 cup of your melty cheese of choice. Repeat one more time: 1/3 of the cream, 1/3 of the potatoes, the remaining fish fillets, and the remaining cup of melty cheese. Finish with one more layer of potatoes and the remaining cream mixture.
Bake:
- Cover loosely with foil and bake for 45 – 60 minutes, or until the potatoes are fork-tender.
- Carefully remove the baking dish from the oven, sprinkle evenly with Parmesan cheese on top, and bake uncovered for 10 minutes or until golden and melty. Remove from the oven and let it rest for 5 minutes before serving.
- Garnish with chopped parsley, if desired. Serve hot.
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- Dairy-Free: To make this recipe dairy-free, you can easily swap out the dairy ingredients for non-dairy alternatives. Cheese: Use your favorite dairy-free melty-style cheese. I like 365 By Whole Foods Market, Cheese Non-Dairy Gouda Slices or MIYOKO’S Fresh Vegan Mozzarella, Organic Classic Plant Milk Cheese. Butter: Use vegan butter instead of dairy butter. Many brands are available in stores. I usually use Earth Balance Vegan Buttery Sticks or Miyoko’s Creamery Organic Vegan Butter. Heavy Cream: You can use a non-dairy cream, such as Silk, Country Crock Plant Cream, or Califia Farms.
Nutrition
Nutrition information provided is an estimate and will vary based on cooking methods and brands of ingredients used.
Recipe Changelog:
- Originally posted in November 2018.
- Update: The post was edited in January 2025 to add more helpful information, with no changes to the recipe.
- Update: The post was updated again in September 2026 to add more helpful information, with no changes to the recipe.
I came across this recipe and was very excited to try it out because I had raw potatoes and frozen whiting that I did not want to go to waste. I followed the recipe step by step and the outcome was very tasty but the creamy sauce was too soupy. Where did I go wrong?
Hello Beth! Thanks for sharing your feedback! I’m curious — did the sauce thicken at all when you cooked it on the stove, or did it stay thin the whole time? That will help me figure out what might have happened.
Can I use a milk sauce bechamel sauce
Hello Linda! Yes, you can definitely use a béchamel sauce. Let me know how it turns out if you give it a try!
This is delicious! I made it as a casserole using tilapia, canned potatoes and green beans. Next time I make it, I’ll add some flour to the layers to make the sauce a little thicker. It reminds us all of cream of crab soup since I replaced the salt with Old Bay. Really good – thanks for the inspiration!
Hello Vicki! It sounds like you nailed it! Thanks so much for trying my recipe and taking the time to come back and let me know.
Hi, sounds delicious, can frozen cod be used? I
Hello Maria! Yes, you can use frozen cod. Thanks for your interest in my recipe. Please come back and let me know how you like it =)
Absolutely delicious!!! My family, that isn’t that big on fish, loved it & asked for seconds! Fabulous!
Hello Sherill! My family loves this one too. Thanks so much for your feedback and for trying my recipe.